OSA's Digital Library

Optics Express

Optics Express

  • Editor: Andrew M. Weiner
  • Vol. 22, Iss. 4 — Feb. 24, 2014
  • pp: 4115–4122
« Show journal navigation

Carrier transfer and thermal escape in CdTe/ZnTe quantum dots

Minh Tan Man and Hong Seok Lee  »View Author Affiliations


Optics Express, Vol. 22, Issue 4, pp. 4115-4122 (2014)
http://dx.doi.org/10.1364/OE.22.004115


View Full Text Article

Acrobat PDF (1776 KB)





Browse Journals / Lookup Meetings

Browse by Journal and Year


   


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

Share
Citations

Abstract

We report on the carrier transfer and thermal escape in CdTe/ZnTe quantum dots (QDs) grown on a GaAs substrate. The significant emission-energy-dependent decay time at high excitation intensity (35 W/cm2) is attributed to the lateral transfer of carriers in the QDs. At low temperature (< 35 K) and low emission energy (< 2.168 eV), a thermally activated transition occurs between two different states separated by approximately 9 meV, while the main contribution to nonradiative processes is the thermal escape from QDs that is assisted by carrier scattering via the emission of longitudinal phonons through the excited QD states at high temperature, with energies of approximately 19 meV.

© 2014 Optical Society of America

1. Introduction

Quantum dots (QDs) are particularly interesting owing to their unique physical properties and their promising applications in high-performance optoelectronic devices such as single-electron transistors [1

1. M. Kroutvar, Y. Ducommun, D. Heiss, M. Bichler, D. Schuh, G. Abstreiter, and J. J. Finley, “Optically programmable electron spin memory using semiconductor quantum dots,” Nature 432(7013), 81–84 (2004). [CrossRef] [PubMed]

], lasers [2

2. E. U. Rafailov, M. A. Cataluna, and W. Sibbett, “Mode-locked quantum-dot lasers,” Nat. Photonics 1(7), 395–401 (2007). [CrossRef]

], light-emitting diodes [3

3. T. X. Lee, K. F. Gao, W. T. Chien, and C. C. Sun, “Light extraction analysis of GaN-based light-emitting diodes with surface texture and/or patterned substrate,” Opt. Express 15(11), 6670–6676 (2007). [CrossRef] [PubMed]

], infrared photodetectors [4

4. S. C. Lee, S. Krishna, and S. R. J. Brueck, “Quantum dot infrared photodetector enhanced by surface plasma wave excitation,” Opt. Express 17(25), 23160–23168 (2009). [CrossRef] [PubMed]

], and solar cells [5

5. D. Guimard, R. Morihara, D. Bordel, K. Tanabe, Y. Wakayama, M. Nishioka, and Y. Arakawa, “Fabrication of InAs/GaAs quantum dot solar cells with enhanced photocurrent and without degradation of open circuit voltage,” Appl. Phys. Lett. 96(20), 203507 (2010). [CrossRef]

]. For these applications, the study of carrier dynamics and time-resolved photoluminescence (PL) in QDs as well as the precise control of shape and size distribution of QDs is very important for improving the performance of optoelectronic devices [6

6. J. H. Lee, J. C. Choi, and H. S. Lee, “Size-dependent carrier dynamics and activation energy in CdTe/ZnTe quantum dots on Si substrates,” J. Mater. Res. 28(11), 1466–1470 (2013). [CrossRef]

]. The study of carrier dynamics not only offers a convenient way to clarify their structures but also provides useful information for extending their applications. Furthermore, time-resolved PL in QDs have emerged as an important tool that helps understand the process of recombination, relaxation, and the interaction between carriers. In particular, wide band-gap CdTe/ZnTe QDs are characterized by high excitonic binding energies and are currently of interest owing to their potential application in optoelectronic devices operating at short wavelengths [7

7. H. S. Lee, H. L. Park, and T. W. Kim, “Optical properties of CdTe/ZnTe quantum dots sandwiched between two quantum wells with ZnTe separation barriers,” Appl. Phys. Lett. 89(18), 181929 (2006). [CrossRef]

, 8

8. W. I. Han, J. H. Lee, J. S. Yu, J. C. Choi, and H. S. Lee, “Carrier dynamics and activation energy of CdTe quantum dots in a CdxZn1−xTe quantum well,” Appl. Phys. Lett. 99(23), 231908 (2011). [CrossRef]

]. A detailed experimental investigation of the recombination and relaxation processes from the barrier states into the discrete energy states involved in optoelectronic devices has thus become necessary. Cascade processes have been generally found to involve radiative relaxation, energy transfer between dots of different dimensions [9

9. G. Gourdon and P. Lavallard, “Exciton transfer between localized states in CdS1−xSex alloys,” Phys. Status Solidi B 153(2), 641–652 (1989). [CrossRef]

], Auger recombination scattering [10

10. V. I. Klimov and D. W. McBranch, “Auger-process-induced charge separation in semiconductor nanocrystals,” Phys. Rev. B 55(19), 13173–13179 (1997). [CrossRef]

], thermal escape from the dot [11

11. W. Yang, R. R. Lowe-Webb, H. Lee, and P. C. Sercel, “Effect of carrier emission and retrapping on luminescence time decays in InAs/GaAs quantum dots,” Phys. Rev. B 56(20), 13314–13320 (1997). [CrossRef]

], or trapping in surface and/or defect states [12

12. V. I. Klimov and D. W. McBranch, “Femtosecond 1P-to-1S electron relaxation in strongly confined semiconductor nanocrystals,” Phys. Rev. Lett. 80(18), 4028–4031 (1998). [CrossRef]

, 13

13. M. C. Nuss, W. Zinth, and W. Kaiser, “Femtosecond carrier relaxation in semiconductor‐doped glasses,” Appl. Phys. Lett. 49(25), 1717–1719 (1986). [CrossRef]

]. Moreover, theoretical study of the nonstationary secondary emission from the lowest-energy states of the QDs has been reported [14

14. I. D. Rukhlenko, M. Y. Leonov, V. K. Turkov, A. P. Litvin, A. S. Baimuratov, A. V. Baranov, and A. V. Fedorov, “Kinetics of pulse-induced photoluminescence from a semiconductor quantum dot,” Opt. Express 20(25), 27612–27635 (2012). [CrossRef] [PubMed]

].

In this paper, we investigate the carrier dynamics in CdTe/ZnTe QDs using time-resolved PL measurements. The analysis of the PL decay time at 20 K as a function of the emission energies clearly indicates that the carrier dynamics can be attributed to the lateral transfer of carriers in the QDs. In addition, we determined localization energy (Elocal), the mobility edge (Eme), and the nonradiative activation energy assisted by the thermal escape process. Using time-resolved PL measurements at various excitation intensities, we also demonstrate that the decreasing decay time as a function of excitation power corresponds to a full filling process of the ground state of each QD, resulting in an increase in the electron-hole wave function overlap with increasing carrier concentration in the dots.

2. Experimental details

The studied sample was grown on a GaAs (100) substrate via molecular beam epitaxy (MBE) and atomic layer epitaxy (ALE). The GaAs substrate was degreased in warm trichloroethylene, cleaned in acetone, cleaned in methanol, and thoroughly rinsed in deionized water. Immediately after the chemical cleaning process, the GaAs substrate was mounted on a molybdenum susceptor. After the GaAs substrate was thermally cleaned at 600 °C for 5 min, a 900 nm ZnTe buffer layer was first grown on the GaAs substrate at 320 °C using MBE, followed by the deposition of 3.5 monolayer (ML) CdTe at 320 °C using ALE, resulting in the formation of QDs. The CdTe QDs were then capped with a 100 nm thick ZnTe layer grown at 320 °C using MBE. The Zn and Te source temperatures for the ZnTe layer were 280 and 300 °C, respectively, while the Cd and Te source temperatures for the CdTe layer were 195 and 300 °C, respectively. One cycle of ALE growth was carried out using an optimum growth process in which the Cd effusion cell was opened for 8 s and growth was interrupted for 1 s. Thereafter, the Te effusion cell was opened for 8 s and growth was interrupted for 5 s. Note that an interrupted process was introduced to improve the film quality by stabilizing positive and negative ions on the surface. Atomic force microscopy (AFM) measurements were performed using a multimode atomic force microscope from Digital Instruments, operating in the tapping mode. Time-resolved PL decay curves were acquired using a time-correlated single photon counting (TCSPC) method. We used 400 nm frequency-doubled femtosecond pulses from a 76 MHz mode-locked Ti:sapphire laser system as an excitation source, and the sample temperature was kept between 20 and 110 K using a He closed-cycle refrigerator displex system. The PL was dispersed using a 15-cm monochromator and detected using a multichannel plate photomultiplier tube. A commercially available TCSPC module (PicoHarp, PicoQuant GmbH) was used to obtain PL decay curves. The full width at half maximum (FWHM) of the total instrument response function (IRF) was less than 130 ps.

3. Results and discussion

Figure 1
Fig. 1 PL spectrum at 20 K for the 3.5 ML CdTe/ZnTe QDs with an excitation power of 1 mW. The inset shows the AFM image of the 3.5 ML CdTe QDs grown on a ZnTe buffer layer.
shows the PL spectrum at 20 K for the 3.5 ML CdTe/ZnTe QDs with an excitation power of 1 mW. The dominant peak at 2.175 eV corresponds to the exciton transition from the ground-state electronic subband to the ground-state heavy-hole band (E1-HH1) in the CdTe/ZnTe QDs. The FWHM of the E1-HH1 peak for the CdTe/ZnTe QDs is approximately 32 meV. The inset of Fig. 1 shows an AFM image of the uncapped surface for the 3.5 ML CdTe/ZnTe QDs. The AFM image reveals that the CdTe QDs are embedded in an undoped ZnTe matrix, and uniform CdTe QDs are formed. The average heights of the formed CdTe QDs are between approximately 7 and 10 nm, and their diameters are between approximately 40 and 50 nm. The density of the CdTe QDs is approximately 5 × 1010 cm−2.

To determine the radiative lifetime of transfer energies triggered at high energies as well as their average localization energy and mobility characteristics, Gourdon and Lavallard [9

9. G. Gourdon and P. Lavallard, “Exciton transfer between localized states in CdS1−xSex alloys,” Phys. Status Solidi B 153(2), 641–652 (1989). [CrossRef]

] proposed an expression for the lateral energy transfer in high-density QDs in the form
τ(ω)=τrad{1+exp[(ωEme)/Elocal]}1
(1)
where τrad is the radiative lifetime, Eme is the energy for which the radiative lifetime equals the lateral transfer time, and Elocal is a characteristic energy for the density of localized states of electrons or holes. The latter parameter is a measure of the average localization energy of the QDs, and Eme could be interpreted as the mobility edge for excitons. We found the best fit value for the radiative lifetime of τ rad to be 480 ps, the best fit for an average localization energy of Elocal to be 9.2 meV, and that for the mobility edge of Eme to be 2.15 eV at 20 K. Interestingly, the strong redshift of Eme is comparable to that of the PL maximum (2.175 eV). It is exciting that the value of Elocal corresponds to the low-energy band. This low energy quenching was assumed to be due to the ionization of shallow donor levels, and the two quenching stages probably point toward a donor-acceptor recombination [23

23. W. Stadler, D. M. Hofmann, H. C. Alt, T. Muschik, B. K. Meyer, E. Weigel, G. Müller-Vogt, M. Salk, E. Rupp, and K. W. Benz, “Optical investigations of defects in Cd1-xZnxTe,” Phys. Rev. B Condens. Matter 51(16), 10619–10630 (1995). [CrossRef] [PubMed]

] or a thermally activated transition from intrinsic states to higher-energy localized surface states [24

24. W. Z. Lee, G. W. Shu, J. S. Wang, J. L. Shen, C. A. Lin, W. H. Chang, R. C. Ruaan, W. C. Chou, H. C. Lu, and Y. C. Lee, “Recombination dynamics of luminescence in colloidal CdSe/ZnS quantum dots,” Nanotechnology 16(9), 1517–1521 (2005). [CrossRef]

], or transitions between intrinsic and defect states [25

25. A. Cretí, M. Anni, M. Zavelani Rossi, G. Lanzani, G. Leo, F. Della Sala, L. Manna, and M. Lomascolo, “Ultrafast carrier dynamics in core and core/shell CdSe quantum rods: Role of the surface and interface defects,” Phys. Rev. B 72(12), 125346 (2005). [CrossRef]

].

For a more adequate description of the carrier dynamics, PL decay times at various temperatures were also considered. Figures 3(a)–(e)
Fig. 3 (a)-(e) Time-resolved PL spectra for peak energies of the 3.5 ML CdTe/ZnTe QDs at several temperatures. (f) Decay time of the 3.5 ML CdTe/ZnTe QDs as a function of temperature. The solid line indicates the fitting curve obtained using the thermal escape model.
show the time-resolved PL spectra for peak energies of the 3.5 ML CdTe/ZnTe QDs at several temperatures. The decay times of the 3.5 ML CdTe/ZnTe QDs as a function of temperature are shown in Fig. 3(f). The results show a significant difference between the coupled and separated QDs, revealing that the transfer processes between different localized states primarily determine the increase of the decay time. Three different processes explain the decay of localized excitons: radiative recombination, transfer processes, and nonradiative recombination. The PL decay time slightly increases for increasing temperatures up to approximately 35 K, and then it decreases with increasing temperature. The increase in the decay times at low temperature is due to heavy-hole coupling, as predicted by the thermal activation of coupled dot, for the carrier wavefunction. The electron-hole overlap is influenced by the electron wave function, while the hole wave function is strongly affected because the coupling of heavy holes is still insufficient to affect the resizing of the dot height. This delocalization is also reported by Colocci et al. [26

26. M. Colocci, A. Vinattieri, L. Lippi, F. Bogani, M. Rosa-Clot, S. Taddei, A. Bosacchi, S. Franchi, and P. Frigeri, “Controlled tuning of the radiative lifetime in InAs self-assembled quantum dots through vertical ordering,” Appl. Phys. Lett. 74(4), 564–566 (1999). [CrossRef]

] in their InAs/GaAs coupled QDs. It is known that at low temperature, the exciton transfer is limited to tunneling processes, whereas the thermally induced coupling between optically active localized excitons and mobile exciton states is enhanced with increasing temperature. In the high temperature region (above 35 K), the PL decay time decreases with increasing temperatures.

In a single approach, the recombination rate of the QD ground state is given by [27

27. M. Gurioli, A. Vinattieri, M. Zamfirescu, M. Colocci, S. Sanguinetti, and R. Nötzel, “Recombination kinetics of InAs quantum dots: Role of thermalization in dark states,” Phys. Rev. B 73(8), 085302 (2006). [CrossRef]

]
Γrec(T)=1/τdecay=ΓR(T)+ΓNR(T)
(2)
where τdecay is the measured PL decay time, and ΓR(T) and ΓNR(T) are the radiative and non-radiative recombination rates, respectively. With the use of these models, it has been reported [28

28. H. Gotoh, H. Ando, and T. Takagahara, “Radiative recombination lifetime of excitons in thin quantum boxes,” J. Appl. Phys. 81(4), 1785–1789 (1997). [CrossRef]

, 29

29. E. Harbord, P. Spencer, E. Clarke, and R. Murray, “Radiative lifetimes in undoped and p-doped InAs/GaAs quantum dots,” Phys. Rev. B 80(19), 195312 (2009). [CrossRef]

] that the thermal population of the higher exciton states, which have lower oscillator strengths, accounts for the prolonged net radiative recombination lifetime in the higher temperature region. The variation of the radiative rate due to the presence of a localized state is given by [29

29. E. Harbord, P. Spencer, E. Clarke, and R. Murray, “Radiative lifetimes in undoped and p-doped InAs/GaAs quantum dots,” Phys. Rev. B 80(19), 195312 (2009). [CrossRef]

]
ΓR(T)=1τ0[1+gexp(ΔE/kBT)]
(3)
where ΔE is the thermally activated energy difference between the ground state and the localized states, g is the ratio of the degeneracy of the localized state to that of the ground state, and τ0 is the radiative time at 0 K. The nonradiative recombination suggests that the main contribution to the nonradiative processes is the thermal escape out of QDs, with the nonradiative recombination rate given by [30

30. M. Gurioli, J. Martinez-Pastor, M. Colocci, C. Deparis, B. Chastaingt, and J. Massies, “Thermal escape of carriers out of GaAs/AlxGa1-xAs quantum-well structures,” Phys. Rev. B Condens. Matter 46(11), 6922–6927 (1992). [CrossRef] [PubMed]

]
ΓNR(T)=Γ0exp(Eesp/kBT)
(4)
where Eesp is the average energy for thermal carrier escape, which corresponds to only one confined level. Γ0 is the escape attempt frequency. For Eq. (2), the above expression becomes:
1τdecay=1τ0[1+gexp(ΔE/kBT)]+Γ0exp(Eesp/kBT)]
(5)
The experimental decay time values are well-reproduced by the best-fit curve to Eq. (5) for ΔE = 9.4 meV, Eesp = 19.3 meV, and τ0 = 484 ps. We observed that the best-fit values of ΔE and τ0 are very similar to Elocal and τrad extracted from the energy-dependent PL decay time analysis, respectively. This suggests that the low-temperature quenching is due to the same thermally activated transition between two different states energetically separated by ΔE. This transition could be due to the transition between intrinsic and defect states that affect the PL decay time temperature dependence at high excitation intensity. For the value of Eesp, it is interesting to note that the carrier escape energy, Eesp, is consistent with the values of average phonon energies obtained on colloidal CdTe QDs [31

31. G. Morello, M. De Giorgi, S. Kudera, L. Manna, R. Cingolani, and M. Anni, “Temperature and size dependence of nonradiative relaxation and exciton-phonon coupling in colloidal CdTe quantum dots,” J. Phys. Chem. C 111(16), 5846–5849 (2007). [CrossRef]

], with a magnitude lower than the theoretical value estimated by Rubin et al. (approximately 24.5 meV for bulk CdTe) [32

32. S. Rudin, T. L. Reinecke, and B. Segall, “Temperature-dependent exciton linewidths in semiconductors,” Phys. Rev. B Condens. Matter 42(17), 11218–11231 (1990). [CrossRef] [PubMed]

]. We expect that thermal carrier escape, which could be due to carrier scattering via emission of longitudinal phonons through the excited QD states, is the main nonradiative process for CdTe/ZnTe QDs at high temperature.

Figure 4(a)
Fig. 4 (a) Time-resolved PL spectra at several excitation intensities for the 3.5 ML CdTe/ZnTe QDs. (b) Decay time of the 3.5 ML CdTe/ZnTe QDs as a function of excitation intensity.
shows the PL decay time obtained from experimental observations at different excitation intensities at 20 K. We compare two PL decay time traces taken with high and low excitation intensities at an emission energy of 2.175 eV [see Fig. 4(b)], at which a change in decay lifetime as a function of excitation intensity at 20 K takes place. This quantity exhibits two distinct regimes. The PL decay time is constant at low excitation power with the average number of excited photons in each dot <N0> << 1, which is sufficiently small to neglect Auger scattering [15

15. V. I. Klimov, D. W. McBranch, C. A. Leatherdale, and M. G. Bawendi, “Electron and hole relaxation pathways in semiconductor quantum dots,” Phys. Rev. B 60(19), 13740–13749 (1999). [CrossRef]

]. At approximately 1 mW, the decay time decreases sublinearly. The decreasing decay time as a function of excitation power corresponds to a full filling process of the ground state of each QD, resulting in an increasing electron-hole wave function overlap with increasing carrier concentration in the dot (primarily heavy-hole). The filling process shows a similar behavior as that reported for InAs/GaAs QDs [33

33. Y. I. Mazur, J. W. Tomm, V. Petrov, G. G. Tarasov, H. Kissel, C. Walther, Z. Y. Zhuchenko, and W. T. Masselink, “Staircase-like spectral dependence of ground-state luminescence time constants in high-density InAs/GaAs quantum dots,” Appl. Phys. Lett. 78(21), 3214–3216 (2001). [CrossRef]

, 34

34. L. Y. Karachinsky, S. Pellegrini, G. S. Buller, A. S. Shkolnik, N. Y. Gordeev, V. P. Evtikhiev, and V. B. Novikov, “Time-resolved photoluminescence measurements of InAs self-assembled quantum dots grown on misorientated substrates,” Appl. Phys. Lett. 84(1), 7–9 (2004). [CrossRef]

]. The observed lifetime shortening at high excitation power with <N0> > 1 is attributed to Auger recombination effects [10

10. V. I. Klimov and D. W. McBranch, “Auger-process-induced charge separation in semiconductor nanocrystals,” Phys. Rev. B 55(19), 13173–13179 (1997). [CrossRef]

]. The efficiency of Auger processes are mediated by strong Coulomb electron-electron interactions in semiconductor QDs [35

35. D. Chatterji, The Theory of Auger Transitions (Academic, 1976).

]. The excess energy of the e-h pair is not efficiently released as a photon, but is instead transferred to a third particle (an electron, a hole, or an exciton) that is re-excited to higher energy states.

4. Conclusion

In conclusion, we have investigated the factors leading to the deterioration of the optical performance in terms of quantum efficiency for CdTe/ZnTe QDs using time-resolved PL measurements at high excitation intensity (35 W/cm2). The significant emission energy-dependent decay time at high excitation intensity is attributed to the lateral transfer of carriers in the QDs. At low temperature and low emission energy, a thermally activated transition occurs between two different states separated by approximately 9 meV, while the main contribution to the nonradiative processes is the thermal escape out of QDs assisted by carrier scattering via emission of longitudinal phonons through the excited QD states at high temperature, with average energies of approximately 19 meV.

Acknowledgments

This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2010-0021189).

References and links

1.

M. Kroutvar, Y. Ducommun, D. Heiss, M. Bichler, D. Schuh, G. Abstreiter, and J. J. Finley, “Optically programmable electron spin memory using semiconductor quantum dots,” Nature 432(7013), 81–84 (2004). [CrossRef] [PubMed]

2.

E. U. Rafailov, M. A. Cataluna, and W. Sibbett, “Mode-locked quantum-dot lasers,” Nat. Photonics 1(7), 395–401 (2007). [CrossRef]

3.

T. X. Lee, K. F. Gao, W. T. Chien, and C. C. Sun, “Light extraction analysis of GaN-based light-emitting diodes with surface texture and/or patterned substrate,” Opt. Express 15(11), 6670–6676 (2007). [CrossRef] [PubMed]

4.

S. C. Lee, S. Krishna, and S. R. J. Brueck, “Quantum dot infrared photodetector enhanced by surface plasma wave excitation,” Opt. Express 17(25), 23160–23168 (2009). [CrossRef] [PubMed]

5.

D. Guimard, R. Morihara, D. Bordel, K. Tanabe, Y. Wakayama, M. Nishioka, and Y. Arakawa, “Fabrication of InAs/GaAs quantum dot solar cells with enhanced photocurrent and without degradation of open circuit voltage,” Appl. Phys. Lett. 96(20), 203507 (2010). [CrossRef]

6.

J. H. Lee, J. C. Choi, and H. S. Lee, “Size-dependent carrier dynamics and activation energy in CdTe/ZnTe quantum dots on Si substrates,” J. Mater. Res. 28(11), 1466–1470 (2013). [CrossRef]

7.

H. S. Lee, H. L. Park, and T. W. Kim, “Optical properties of CdTe/ZnTe quantum dots sandwiched between two quantum wells with ZnTe separation barriers,” Appl. Phys. Lett. 89(18), 181929 (2006). [CrossRef]

8.

W. I. Han, J. H. Lee, J. S. Yu, J. C. Choi, and H. S. Lee, “Carrier dynamics and activation energy of CdTe quantum dots in a CdxZn1−xTe quantum well,” Appl. Phys. Lett. 99(23), 231908 (2011). [CrossRef]

9.

G. Gourdon and P. Lavallard, “Exciton transfer between localized states in CdS1−xSex alloys,” Phys. Status Solidi B 153(2), 641–652 (1989). [CrossRef]

10.

V. I. Klimov and D. W. McBranch, “Auger-process-induced charge separation in semiconductor nanocrystals,” Phys. Rev. B 55(19), 13173–13179 (1997). [CrossRef]

11.

W. Yang, R. R. Lowe-Webb, H. Lee, and P. C. Sercel, “Effect of carrier emission and retrapping on luminescence time decays in InAs/GaAs quantum dots,” Phys. Rev. B 56(20), 13314–13320 (1997). [CrossRef]

12.

V. I. Klimov and D. W. McBranch, “Femtosecond 1P-to-1S electron relaxation in strongly confined semiconductor nanocrystals,” Phys. Rev. Lett. 80(18), 4028–4031 (1998). [CrossRef]

13.

M. C. Nuss, W. Zinth, and W. Kaiser, “Femtosecond carrier relaxation in semiconductor‐doped glasses,” Appl. Phys. Lett. 49(25), 1717–1719 (1986). [CrossRef]

14.

I. D. Rukhlenko, M. Y. Leonov, V. K. Turkov, A. P. Litvin, A. S. Baimuratov, A. V. Baranov, and A. V. Fedorov, “Kinetics of pulse-induced photoluminescence from a semiconductor quantum dot,” Opt. Express 20(25), 27612–27635 (2012). [CrossRef] [PubMed]

15.

V. I. Klimov, D. W. McBranch, C. A. Leatherdale, and M. G. Bawendi, “Electron and hole relaxation pathways in semiconductor quantum dots,” Phys. Rev. B 60(19), 13740–13749 (1999). [CrossRef]

16.

B. Valeur, Molecular Fluorescence (Wiley-VCH, 2002).

17.

O. Labeau, P. Tamarat, and B. Lounis, “Temperature dependence of the luminescence lifetime of single CdSe/ZnS quantum dots,” Phys. Rev. Lett. 90(25), 257404 (2003). [CrossRef] [PubMed]

18.

A. Nakamura, H. Yamada, and T. Tokizaki, “Size-dependent radiative decay of excitons in CuCl semiconducting quantum spheres embedded in glasses,” Phys. Rev. B Condens. Matter 40(12), 8585–8588 (1989). [CrossRef] [PubMed]

19.

T. Itoh, M. Furumiya, T. Ikehara, and C. Gourdon, “Size-dependent radiative decay time of confined excitons in CuCl microcrystals,” Solid State Commun. 73(4), 271–274 (1990). [CrossRef]

20.

W. Ouerghui, J. Martinez-Pastor, J. Gomis, M. A. Maaref, D. Granados, and J. M. Garcia, “Lateral carrier tunnelling in stacked In(Ga)As/GaAs quantum rings,” Eur. Phys. J. B 54(2), 217–223 (2006). [CrossRef]

21.

I. L. Krestnikov, N. N. Ledentsov, A. Hoffmann, D. Bimberg, A. V. Sakharov, W. V. Lundin, A. F. Tsatsul’nikov, A. S. Usikov, Zh. I. Alferov, Yu. G. Musikhin, and D. Gerthsen, “Quantum dot origin of luminescence in InGaN-GaN structures,” Phys. Rev. B 66(15), 155310 (2002). [CrossRef]

22.

P. Bigenwald, P. Lefebvre, T. Bretagnon, and B. Gil, “Confined excitons in GaN-AlGaN quantum wells,” Phys. Status Solidi B 216(1), 371–374 (1999). [CrossRef]

23.

W. Stadler, D. M. Hofmann, H. C. Alt, T. Muschik, B. K. Meyer, E. Weigel, G. Müller-Vogt, M. Salk, E. Rupp, and K. W. Benz, “Optical investigations of defects in Cd1-xZnxTe,” Phys. Rev. B Condens. Matter 51(16), 10619–10630 (1995). [CrossRef] [PubMed]

24.

W. Z. Lee, G. W. Shu, J. S. Wang, J. L. Shen, C. A. Lin, W. H. Chang, R. C. Ruaan, W. C. Chou, H. C. Lu, and Y. C. Lee, “Recombination dynamics of luminescence in colloidal CdSe/ZnS quantum dots,” Nanotechnology 16(9), 1517–1521 (2005). [CrossRef]

25.

A. Cretí, M. Anni, M. Zavelani Rossi, G. Lanzani, G. Leo, F. Della Sala, L. Manna, and M. Lomascolo, “Ultrafast carrier dynamics in core and core/shell CdSe quantum rods: Role of the surface and interface defects,” Phys. Rev. B 72(12), 125346 (2005). [CrossRef]

26.

M. Colocci, A. Vinattieri, L. Lippi, F. Bogani, M. Rosa-Clot, S. Taddei, A. Bosacchi, S. Franchi, and P. Frigeri, “Controlled tuning of the radiative lifetime in InAs self-assembled quantum dots through vertical ordering,” Appl. Phys. Lett. 74(4), 564–566 (1999). [CrossRef]

27.

M. Gurioli, A. Vinattieri, M. Zamfirescu, M. Colocci, S. Sanguinetti, and R. Nötzel, “Recombination kinetics of InAs quantum dots: Role of thermalization in dark states,” Phys. Rev. B 73(8), 085302 (2006). [CrossRef]

28.

H. Gotoh, H. Ando, and T. Takagahara, “Radiative recombination lifetime of excitons in thin quantum boxes,” J. Appl. Phys. 81(4), 1785–1789 (1997). [CrossRef]

29.

E. Harbord, P. Spencer, E. Clarke, and R. Murray, “Radiative lifetimes in undoped and p-doped InAs/GaAs quantum dots,” Phys. Rev. B 80(19), 195312 (2009). [CrossRef]

30.

M. Gurioli, J. Martinez-Pastor, M. Colocci, C. Deparis, B. Chastaingt, and J. Massies, “Thermal escape of carriers out of GaAs/AlxGa1-xAs quantum-well structures,” Phys. Rev. B Condens. Matter 46(11), 6922–6927 (1992). [CrossRef] [PubMed]

31.

G. Morello, M. De Giorgi, S. Kudera, L. Manna, R. Cingolani, and M. Anni, “Temperature and size dependence of nonradiative relaxation and exciton-phonon coupling in colloidal CdTe quantum dots,” J. Phys. Chem. C 111(16), 5846–5849 (2007). [CrossRef]

32.

S. Rudin, T. L. Reinecke, and B. Segall, “Temperature-dependent exciton linewidths in semiconductors,” Phys. Rev. B Condens. Matter 42(17), 11218–11231 (1990). [CrossRef] [PubMed]

33.

Y. I. Mazur, J. W. Tomm, V. Petrov, G. G. Tarasov, H. Kissel, C. Walther, Z. Y. Zhuchenko, and W. T. Masselink, “Staircase-like spectral dependence of ground-state luminescence time constants in high-density InAs/GaAs quantum dots,” Appl. Phys. Lett. 78(21), 3214–3216 (2001). [CrossRef]

34.

L. Y. Karachinsky, S. Pellegrini, G. S. Buller, A. S. Shkolnik, N. Y. Gordeev, V. P. Evtikhiev, and V. B. Novikov, “Time-resolved photoluminescence measurements of InAs self-assembled quantum dots grown on misorientated substrates,” Appl. Phys. Lett. 84(1), 7–9 (2004). [CrossRef]

35.

D. Chatterji, The Theory of Auger Transitions (Academic, 1976).

OCIS Codes
(160.4760) Materials : Optical properties
(260.3800) Physical optics : Luminescence
(300.6500) Spectroscopy : Spectroscopy, time-resolved
(250.5590) Optoelectronics : Quantum-well, -wire and -dot devices

ToC Category:
Materials

History
Original Manuscript: November 13, 2013
Revised Manuscript: January 24, 2014
Manuscript Accepted: January 24, 2014
Published: February 14, 2014

Virtual Issues
Vol. 9, Iss. 4 Virtual Journal for Biomedical Optics

Citation
Minh Tan Man and Hong Seok Lee, "Carrier transfer and thermal escape in CdTe/ZnTe quantum dots," Opt. Express 22, 4115-4122 (2014)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-22-4-4115


Sort:  Author  |  Year  |  Journal  |  Reset  

References

  1. M. Kroutvar, Y. Ducommun, D. Heiss, M. Bichler, D. Schuh, G. Abstreiter, J. J. Finley, “Optically programmable electron spin memory using semiconductor quantum dots,” Nature 432(7013), 81–84 (2004). [CrossRef] [PubMed]
  2. E. U. Rafailov, M. A. Cataluna, W. Sibbett, “Mode-locked quantum-dot lasers,” Nat. Photonics 1(7), 395–401 (2007). [CrossRef]
  3. T. X. Lee, K. F. Gao, W. T. Chien, C. C. Sun, “Light extraction analysis of GaN-based light-emitting diodes with surface texture and/or patterned substrate,” Opt. Express 15(11), 6670–6676 (2007). [CrossRef] [PubMed]
  4. S. C. Lee, S. Krishna, S. R. J. Brueck, “Quantum dot infrared photodetector enhanced by surface plasma wave excitation,” Opt. Express 17(25), 23160–23168 (2009). [CrossRef] [PubMed]
  5. D. Guimard, R. Morihara, D. Bordel, K. Tanabe, Y. Wakayama, M. Nishioka, Y. Arakawa, “Fabrication of InAs/GaAs quantum dot solar cells with enhanced photocurrent and without degradation of open circuit voltage,” Appl. Phys. Lett. 96(20), 203507 (2010). [CrossRef]
  6. J. H. Lee, J. C. Choi, H. S. Lee, “Size-dependent carrier dynamics and activation energy in CdTe/ZnTe quantum dots on Si substrates,” J. Mater. Res. 28(11), 1466–1470 (2013). [CrossRef]
  7. H. S. Lee, H. L. Park, T. W. Kim, “Optical properties of CdTe/ZnTe quantum dots sandwiched between two quantum wells with ZnTe separation barriers,” Appl. Phys. Lett. 89(18), 181929 (2006). [CrossRef]
  8. W. I. Han, J. H. Lee, J. S. Yu, J. C. Choi, H. S. Lee, “Carrier dynamics and activation energy of CdTe quantum dots in a CdxZn1−xTe quantum well,” Appl. Phys. Lett. 99(23), 231908 (2011). [CrossRef]
  9. G. Gourdon, P. Lavallard, “Exciton transfer between localized states in CdS1−xSex alloys,” Phys. Status Solidi B 153(2), 641–652 (1989). [CrossRef]
  10. V. I. Klimov, D. W. McBranch, “Auger-process-induced charge separation in semiconductor nanocrystals,” Phys. Rev. B 55(19), 13173–13179 (1997). [CrossRef]
  11. W. Yang, R. R. Lowe-Webb, H. Lee, P. C. Sercel, “Effect of carrier emission and retrapping on luminescence time decays in InAs/GaAs quantum dots,” Phys. Rev. B 56(20), 13314–13320 (1997). [CrossRef]
  12. V. I. Klimov, D. W. McBranch, “Femtosecond 1P-to-1S electron relaxation in strongly confined semiconductor nanocrystals,” Phys. Rev. Lett. 80(18), 4028–4031 (1998). [CrossRef]
  13. M. C. Nuss, W. Zinth, W. Kaiser, “Femtosecond carrier relaxation in semiconductor‐doped glasses,” Appl. Phys. Lett. 49(25), 1717–1719 (1986). [CrossRef]
  14. I. D. Rukhlenko, M. Y. Leonov, V. K. Turkov, A. P. Litvin, A. S. Baimuratov, A. V. Baranov, A. V. Fedorov, “Kinetics of pulse-induced photoluminescence from a semiconductor quantum dot,” Opt. Express 20(25), 27612–27635 (2012). [CrossRef] [PubMed]
  15. V. I. Klimov, D. W. McBranch, C. A. Leatherdale, M. G. Bawendi, “Electron and hole relaxation pathways in semiconductor quantum dots,” Phys. Rev. B 60(19), 13740–13749 (1999). [CrossRef]
  16. B. Valeur, Molecular Fluorescence (Wiley-VCH, 2002).
  17. O. Labeau, P. Tamarat, B. Lounis, “Temperature dependence of the luminescence lifetime of single CdSe/ZnS quantum dots,” Phys. Rev. Lett. 90(25), 257404 (2003). [CrossRef] [PubMed]
  18. A. Nakamura, H. Yamada, T. Tokizaki, “Size-dependent radiative decay of excitons in CuCl semiconducting quantum spheres embedded in glasses,” Phys. Rev. B Condens. Matter 40(12), 8585–8588 (1989). [CrossRef] [PubMed]
  19. T. Itoh, M. Furumiya, T. Ikehara, C. Gourdon, “Size-dependent radiative decay time of confined excitons in CuCl microcrystals,” Solid State Commun. 73(4), 271–274 (1990). [CrossRef]
  20. W. Ouerghui, J. Martinez-Pastor, J. Gomis, M. A. Maaref, D. Granados, J. M. Garcia, “Lateral carrier tunnelling in stacked In(Ga)As/GaAs quantum rings,” Eur. Phys. J. B 54(2), 217–223 (2006). [CrossRef]
  21. I. L. Krestnikov, N. N. Ledentsov, A. Hoffmann, D. Bimberg, A. V. Sakharov, W. V. Lundin, A. F. Tsatsul’nikov, A. S. Usikov, Zh. I. Alferov, Yu. G. Musikhin, D. Gerthsen, “Quantum dot origin of luminescence in InGaN-GaN structures,” Phys. Rev. B 66(15), 155310 (2002). [CrossRef]
  22. P. Bigenwald, P. Lefebvre, T. Bretagnon, B. Gil, “Confined excitons in GaN-AlGaN quantum wells,” Phys. Status Solidi B 216(1), 371–374 (1999). [CrossRef]
  23. W. Stadler, D. M. Hofmann, H. C. Alt, T. Muschik, B. K. Meyer, E. Weigel, G. Müller-Vogt, M. Salk, E. Rupp, K. W. Benz, “Optical investigations of defects in Cd1-xZnxTe,” Phys. Rev. B Condens. Matter 51(16), 10619–10630 (1995). [CrossRef] [PubMed]
  24. W. Z. Lee, G. W. Shu, J. S. Wang, J. L. Shen, C. A. Lin, W. H. Chang, R. C. Ruaan, W. C. Chou, H. C. Lu, Y. C. Lee, “Recombination dynamics of luminescence in colloidal CdSe/ZnS quantum dots,” Nanotechnology 16(9), 1517–1521 (2005). [CrossRef]
  25. A. Cretí, M. Anni, M. Zavelani Rossi, G. Lanzani, G. Leo, F. Della Sala, L. Manna, M. Lomascolo, “Ultrafast carrier dynamics in core and core/shell CdSe quantum rods: Role of the surface and interface defects,” Phys. Rev. B 72(12), 125346 (2005). [CrossRef]
  26. M. Colocci, A. Vinattieri, L. Lippi, F. Bogani, M. Rosa-Clot, S. Taddei, A. Bosacchi, S. Franchi, P. Frigeri, “Controlled tuning of the radiative lifetime in InAs self-assembled quantum dots through vertical ordering,” Appl. Phys. Lett. 74(4), 564–566 (1999). [CrossRef]
  27. M. Gurioli, A. Vinattieri, M. Zamfirescu, M. Colocci, S. Sanguinetti, R. Nötzel, “Recombination kinetics of InAs quantum dots: Role of thermalization in dark states,” Phys. Rev. B 73(8), 085302 (2006). [CrossRef]
  28. H. Gotoh, H. Ando, T. Takagahara, “Radiative recombination lifetime of excitons in thin quantum boxes,” J. Appl. Phys. 81(4), 1785–1789 (1997). [CrossRef]
  29. E. Harbord, P. Spencer, E. Clarke, R. Murray, “Radiative lifetimes in undoped and p-doped InAs/GaAs quantum dots,” Phys. Rev. B 80(19), 195312 (2009). [CrossRef]
  30. M. Gurioli, J. Martinez-Pastor, M. Colocci, C. Deparis, B. Chastaingt, J. Massies, “Thermal escape of carriers out of GaAs/AlxGa1-xAs quantum-well structures,” Phys. Rev. B Condens. Matter 46(11), 6922–6927 (1992). [CrossRef] [PubMed]
  31. G. Morello, M. De Giorgi, S. Kudera, L. Manna, R. Cingolani, M. Anni, “Temperature and size dependence of nonradiative relaxation and exciton-phonon coupling in colloidal CdTe quantum dots,” J. Phys. Chem. C 111(16), 5846–5849 (2007). [CrossRef]
  32. S. Rudin, T. L. Reinecke, B. Segall, “Temperature-dependent exciton linewidths in semiconductors,” Phys. Rev. B Condens. Matter 42(17), 11218–11231 (1990). [CrossRef] [PubMed]
  33. Y. I. Mazur, J. W. Tomm, V. Petrov, G. G. Tarasov, H. Kissel, C. Walther, Z. Y. Zhuchenko, W. T. Masselink, “Staircase-like spectral dependence of ground-state luminescence time constants in high-density InAs/GaAs quantum dots,” Appl. Phys. Lett. 78(21), 3214–3216 (2001). [CrossRef]
  34. L. Y. Karachinsky, S. Pellegrini, G. S. Buller, A. S. Shkolnik, N. Y. Gordeev, V. P. Evtikhiev, V. B. Novikov, “Time-resolved photoluminescence measurements of InAs self-assembled quantum dots grown on misorientated substrates,” Appl. Phys. Lett. 84(1), 7–9 (2004). [CrossRef]
  35. D. Chatterji, The Theory of Auger Transitions (Academic, 1976).

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

Figures

Fig. 1 Fig. 2 Fig. 3
 
Fig. 4
 

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited