## Temperature dependence of the radiative recombination time in ZnO nanorods under an external magnetic field of 6T |

Optics Express, Vol. 22, Issue 15, pp. 17959-17967 (2014)

http://dx.doi.org/10.1364/OE.22.017959

Acrobat PDF (2542 KB)

### Abstract

The Temperature dependence of the exciton radiative decay time in ZnO nanorods has been investigated, which is associated with the density of states for the intra-relaxation of thermally excited excitons. The photoluminescence decay time was calibrated by using the photoluminescence intensity in order to obtain the radiative decay time. In the absence of an external magnetic field, we have confirmed that the radiative decay time increased with temperature in a similar manner to that seen in bulk material (∼ *T*^{1.5}). Under an external magnetic field of 6T parallel to the *c*-axis, we found that the power coefficient of the radiative decay time with temperature decreased (∼ *T*^{1.3}) when compared to that in the absence of a magnetic field. This result can be attributed to an enhancement of the effective mass perpendicular to the magnetic field and a redshift of the center-of-mass exciton as a consequence of perturbation effects in the weak-field regime.

© 2014 Optical Society of America

## 1. Introduction

3. S. Schimitt-Rink, J. B. Stark, W. H. Knox, D. S. Chemla, and W. Schäfer, “Optical properties of quasi-zero-dimensional magneto-excitons,” Appl. Phys. A **53**, 491–502 (1991). [CrossRef]

4. Y. D. Jho, Xiaoming Wang, J. Kono, D. H. Reitze, X. Wei, A. A. Belyanin, V. V. Kocharovsky, Vl. V. Kocharovsky, and G. S. Solomon, “Cooperative Recombination of a Quantized High-Density Electron-Hole Plasma in Semiconductor Quantum Wells,” Phys. Rev. Lett. **96**, 237401 (2006). [CrossRef] [PubMed]

*h̄ω*

_{c}) is larger than the exciton binding energy (

5. Claus F. Klingshirn, *Semiconductor Optics*, 4th Edition (Springer, 2012). [CrossRef]

6. G. W. ’t Hooft, W. A. J. A. van der Poel, L. W. Molenkamp, and C. T. Foxon, “Giant oscillator strength of free excitons in GaAs,” Phys. Rev. B **35**, 8281–8284 (1987). [CrossRef]

7. H. Akiyama, S. Koshiba, T. Someya, K. Wada, H. Noge, Y. Nakamura, T. Inoshita, and A. Shimizu, “Thermalization Effect on Radiative Decay of Exciton in Quantum Wires,” Phys. Rev. Lett. **72**, 924–927 (1994). [CrossRef] [PubMed]

7. H. Akiyama, S. Koshiba, T. Someya, K. Wada, H. Noge, Y. Nakamura, T. Inoshita, and A. Shimizu, “Thermalization Effect on Radiative Decay of Exciton in Quantum Wires,” Phys. Rev. Lett. **72**, 924–927 (1994). [CrossRef] [PubMed]

5. Claus F. Klingshirn, *Semiconductor Optics*, 4th Edition (Springer, 2012). [CrossRef]

8. F. V. Kyrychenko, Y. D. Jho, J. Kono, S. A. Cooker, G. D. Sanders, D. H. Reitze, C. J. Stanton, X. Wei, C. Kadow, and A. C. Gossard, “Interband magnetoabsorption study of the shift of the Fermi energy of a 2DEG with an in-plane magnetic field,” Phisica E **22**, 624–627 (2004). [CrossRef]

*τ*

_{r}) with and without an external magnetic field. For large diameter ZnO nanorods (250nm) in the absence of a magnetic field, a bulk nature was confirmed (

*τ*

_{r}∼

*T*

^{1.5}). On the other hand, when 6T is applied (the weak-field regime), we conclude that the perturbation effect of the weak magnetic field results in a quasi-dimensionality between 2D and 3D according to the power coefficient of the radiative decay time with temperature (

*τ*

_{r}∼

*T*

^{1.3}).

## 2. Experiment

*c*-plane sapphire in a horizontal reactor operating at a reduced pressure of 50 Torr. Diethylzinc (DEZn) and nitrous oxide (N

_{2}O) were used as the zinc and oxygen sources with helium gas. The concentration of DEZn was 40

*μ*mol/mn. Vertical ZnO nanorods with high aspect ratio and hexagonal section were grown at 875 °C under moderate oxygen/zinc molar ratio (R

_{VI/II}) of 1150 in order to favor 1D growth (high R

_{VI/II}above 14000 leads to two dimensional layer growth). The deposition time is 40 minutes [9]. Top and side views of SEM images of the nanorods are shown in Fig. 1(a), where a single rod is of 5

*μ*m length and hexagonal type and its diameter is approximately 250 nm. Third harmonic emission (266nm) generated from a Ti:sapphire laser (∼ 800nm) emitting pulses of 80fs duration operating at a repetition frequency of 80MHz was used for excitation. In order to avoid many-body effects, a weak excitation intensity (10pJ per pulse) was used. The beam was focused onto the sample mounted in a temperature-controlled cryostat housing a superconducting magnet, where an external magnetic flux density of 6T was applied parallel to the nanorod direction. Time-resolved photoluminescence (TR-PL) was measured by using a streak camera.

## 3. Results and discussion

10. X. H. Zhang, S. J. Chua, A. M. Yong, H. Y. Yang, S. P. Lau, S. F. Yu, X. W. Sun, Lei Miao, Masaki Tanemura, and Sakae Tanemura, “Exciton radiative lifetime in ZnO nanorods fabricated by vapor phase transport method,” Appl. Phys. Lett. **90**, 013107 (2007). [CrossRef]

11. Fang-Yi Jen, Yen-Cheng Lu, Cheng-Yen Chen, Hsiang-Chen Wang, C. C. Yang, Bao-ping Zhang, and Yusaburo Segawa, “Temperature-dependent exciton dynamics in a ZnO thin film,” Appl. Phys. Lett. **87**, 252117 (2005). [CrossRef]

^{0}Xs), free excitons (FXs) need to be resolved from the PL spectrum in order to evaluate the dimensional nature of the recombination. Secondly, the excitation intensity should be low enough to avoid many-body effects. As our excitation intensity (0.1

*μ*Jcm

^{−2}) is lower by two-orders of magnitude compared to that of reported work (40

*μ*Jcm

^{−2}), bandgap renormalization can be ruled out. Thirdly, the temperatures used should be low, otherwise the extraction of a pure radiative decay time becomes difficult as thermal non-radiative processes become significant, such as thermal dissociation, excitation, and quenching.

^{0}Xs and FXs with and without external magnetic field were resolved for various temperatures by double Gaussian fitting [12]. Although various peaks are seen at energies below that of the D

^{0}X, which are possibly other kinds of donor-bound excitons, acceptor-bound excitons, and exciton LO-phonon replicas, we include the D

^{0}Xs to improve the fitting accuracy of the FXs. Given the fitted linewidths of FXs (∼ 15meV), it was not possible to resolve the two peaks expected from the small Zeeman splitting (∼ 0.9meV) under an external magnetic flux density of 6T, which was estimated by using the

*g*-factor of the electron (1.957) and the hole (2.45) in ZnO [13

13. Walter R. L. Lambrecht, Anna V. Rodina, Sukit Limpijumnong, B. Segall, and Bruno K. Meyer, “Valence-band ordering and magneto-optic exciton fine structure in ZnO,” Phys. Rev. B **65**, 075207 (2002). [CrossRef]

8. F. V. Kyrychenko, Y. D. Jho, J. Kono, S. A. Cooker, G. D. Sanders, D. H. Reitze, C. J. Stanton, X. Wei, C. Kadow, and A. C. Gossard, “Interband magnetoabsorption study of the shift of the Fermi energy of a 2DEG with an in-plane magnetic field,” Phisica E **22**, 624–627 (2004). [CrossRef]

*k*-range where the center-of-mass FX wave vector is small when compared to that of the photon (

*k*<

*k*

_{0}) at finite temperature, where

*k*

_{0}is determined by the intersection of the parabolic center-of-mass FX dispersion (

*E*=

*h̄*

^{2}

*k*

^{2}/2

*M*) and the linear photon dispersion (

*M*= 0.69

*m*

_{0}) and the dielectric constant

*ε*

_{0}(

*ε*

_{∞}) = 8.656(3.67), where

*m*

_{0}is the electron rest mass, the maximum kinetic energy for radiative decay of the FXs (

14. S. J. Pearton, D. P. Norton, K. Ip, Y. W. Heo, and T. Steiner, “Recent advances in processing of ZnO,” J. Vac. Sci. Technol. B **22**, 932–948 (2004). [CrossRef]

15. Brendan Enright and Donald Fizmaurice, “Spectroscopic Determination of Electron and Hole Effective Masses in a Nanocrystalline Semiconductor Film,” J. Phys. Chem. **100**, 1027–1035 (1996). [CrossRef]

*k*>

*k*

_{0}) the decay is dominated by non-radiative processes during their intra-relaxation along the dispersion via various inelastic scattering processes to conserve their momentum. As a result, the PL decay time (

*τ*) represents the population decay as a consequence of both radiative and non-radiative processes. Provided that high quality samples are measured at very low temperature (< 10K), the non-radiative decay can be negligible [6

6. G. W. ’t Hooft, W. A. J. A. van der Poel, L. W. Molenkamp, and C. T. Foxon, “Giant oscillator strength of free excitons in GaAs,” Phys. Rev. B **35**, 8281–8284 (1987). [CrossRef]

*τ*

_{nr}) needs to be considered in the PL decay.

*N*) after transient excitation (

*g*) is given by whereby the population in the steady state

*N*=

*gτ*can also be obtained. As long as the relation 1/

*τ*= 1/

*τ*

_{r}+ 1/

*τ*

_{nr}holds true, the time-integrated PL intensity at a given temperature can be described as

*I*(

*T*) ∼

*N/τ*

_{r}(

*T*) =

*gη*(

*T*), where

*η*(

*T*) =

*τ/τ*

_{r}is the quantum efficiency for that temperature [16

16. R. C. Miller, D. A. Kleinman, W. A. Nordland Jr., and A. C. Gossard, “Luminescence studies of optically pumped quantum wells in GaAs-Al_{x}Ga_{1−}_{x}As multilayer structures,” Phys. Rev. B **22**, 863–871 (1980). [CrossRef]

*I*(

*T*) to

*I*(4K) represents the ratio of (

*T*) to (4K) as where the calibration factor

*ζ*(

*T*) enables us to measure the temperature dependence of the radiative decay time in terms of

*τ*

_{r}(

*T*)

*η*(4K) as [17

17. D. Takamizu, Y. Nishimoto, S. Akasaka, H. Yuji, K. Tamura, K. Nakahara, T. Onuma, T. Tanabe, H. Takasu, M. Kawasaki, and S. F. Chichibu, “Direct correlation between the internal quantum efficiency and photoluminescence lifetime in undoped ZnO epilayers grown on Zn-polar ZnO substrates by plasma-assisted molecular beam epitaxy,” J. Appl. Phys. **103**, 063502 (2008). [CrossRef]

*η*(4K)) is unknown, the temperature dependence of the radiative decay time can be analyzed in terms of the power order (

*α*) as

*τ*

_{r}(

*T*) ∼

*T*, i.e.,

^{α}*η*(4K) contributes as a scaling factor, but does not change

*α*.

*τ*

_{r}(

*T*) is given by where

*τ*

_{0}is the intrinsic radiative decay time of the FX at

*k*∼ 0 and

*k*

_{B}is the Boltzmann constant. The fraction of the small wave vector FXs (

*k*<

*k*

_{0}) with respect to the thermally excited ones (

*r*(

*T*)) is associated with the exciton density of states for a given energy (

*ε*) as

*D*(

*ε*)∼

*ε*. Because

^{β}*β*depends on the confinement dimension, the dimensional nature of the nanorod can be determined in terms of

*α*. As a result, the power order of the density of states (

*β*= −0.5, 0, 0.5) for 1D, 2D, and 3D determines the power order of the temperature dependence (

*α*= 0.5, 1, 1.5), respectively [6

6. G. W. ’t Hooft, W. A. J. A. van der Poel, L. W. Molenkamp, and C. T. Foxon, “Giant oscillator strength of free excitons in GaAs,” Phys. Rev. B **35**, 8281–8284 (1987). [CrossRef]

7. H. Akiyama, S. Koshiba, T. Someya, K. Wada, H. Noge, Y. Nakamura, T. Inoshita, and A. Shimizu, “Thermalization Effect on Radiative Decay of Exciton in Quantum Wires,” Phys. Rev. Lett. **72**, 924–927 (1994). [CrossRef] [PubMed]

*τ*(

*T*) obtained from the monotonic decay of the TR-PL in the absence and presence of a magnetic field (Figs. 2(a) and 2(b)). The temperature dependence of the calibration factor

*ζ*(

*T*) was also obtained by normalizing

*I*(

*T*) to

*I*(4K) as shown in Fig. 2(d). While

*τ*(

*T*) increases with temperature, a critical change in the temperature dependence is seen beyond 40K, where

*I*(

*T*) also becomes significantly suppressed (insets of Figs. 2(c) and 2(d)). These results indicate that the PL decay is dominated by non-radiative decay due to thermal effects when the temperature increases beyond 40K. It should also be noted that the accuracy of

*τ*(

*T*) deteriorates when the temperature is higher than 40K. Although Figs. 2(a) and 2(b) are normalized, the raw intensity weakens with a small signal-to-noise ratio as the temperature rises. As a result, the error bar for

*τ*(

*T*) becomes large. Since the dimensional nature of the nanorod is associated with radiative decay processes,

*α*should be obtained by considering lifetime data below the critical temperature (< 40K) only. The enhancement of

*η*(

*T*) up to ∼ 40K can be attributed to suppression of FX trapping to donors [18

18. W. I. Park, Y. H. Jun, S. W. Jung, and Gyu-Chul Yi, “Excitonic emissions observed in ZnO single crystal nanorods,” Appl. Phys. Lett. **82**, 964–966 (2003). [CrossRef]

*et al.*measured a quadratic dependence for

*τ*(

*T*), but calibration was overlooked [10

10. X. H. Zhang, S. J. Chua, A. M. Yong, H. Y. Yang, S. P. Lau, S. F. Yu, X. W. Sun, Lei Miao, Masaki Tanemura, and Sakae Tanemura, “Exciton radiative lifetime in ZnO nanorods fabricated by vapor phase transport method,” Appl. Phys. Lett. **90**, 013107 (2007). [CrossRef]

*et al.*considered the temperature dependence of the integrated PL intensity in order to calibrate

*τ*(

*T*), a linear temperature dependence of

*τ*

_{r}(

*T*) was obtained in a ZnO film, which is in contrast to the 3D case (

*τ*

_{r}(

*T*) ∼

*T*

^{1.5}). This disagreement possibly results from the inappropriate temperature range. Because the temperature dependence of the FXs was considered from 40K up to 180K [11

11. Fang-Yi Jen, Yen-Cheng Lu, Cheng-Yen Chen, Hsiang-Chen Wang, C. C. Yang, Bao-ping Zhang, and Yusaburo Segawa, “Temperature-dependent exciton dynamics in a ZnO thin film,” Appl. Phys. Lett. **87**, 252117 (2005). [CrossRef]

*τ*(

*T*) by the calibration factor (

*ζ*(

*T*)) for the temperature dependence of the radiative decay time according to Eq. (3), the power-order of

*τ*

_{r}(

*T*) decreases when compared to that of

*τ*(

*T*). As shown in Fig. 3(a), we have confirmed that the temperature dependence of

*τ*

_{r}(

*T*) in our ZnO nanorods follows that expected for the bulk case (∼

*T*

^{1.5}). Given that the unknown

*η*(4K) is less than 1,

*τ*

_{r}(

*T*) seems somewhat long compared to the tens of picoseconds expected for the intrinsic radiative decay time in a semiconductor due to the long range spatial coherence of the small

*k*. This can be explained by the large PL linewidth of the FXs in the nanorods; when the linewidth broadening is large, the uncertainty of the wave vector becomes comparable to

*k*

_{0}. This limits the spatial coherence by localization, resulting in a relatively long radiative decay time.

**k**) in

**k**-space for the various coordinate configurations (

*k*

_{x},

*k*

_{y},

*k*

_{z}). On the other hand, an external magnetic field gives rise to quantized Landau levels in the magnetically-induced parabolic potential for the rotating radius. Schematically, the equally spaced (Δ

**k**) points in the

**k**-plane (

*k*

_{x},

*k*

_{y}), which represent the states in the absence of magnetic field, turn into the rings, which correspond to the Landau levels in the presence of an external magnetic field. The lateral distance between the rings in the

**k**-plane (Δ

**k**

_{m}) decreases as the Landau levels are equidistant in energy. As a result, the density of states is reduced in the presence of an external magnetic field [19, 20].

*h̄ω*

_{c}) compared to the exciton binding energy (

*ω*

_{c}=

*eB/μ*) can be estimated by the reduced mass of the exciton (

*μ*) and the applied magnetic flux density (

*Bẑ*). Therefore, a 1D nature can be claimed in the so-called strong-field regime (

*h̄ω*

_{c}∼ 4.4meV) is still less than the exciton binding energy (

5. Claus F. Klingshirn, *Semiconductor Optics*, 4th Edition (Springer, 2012). [CrossRef]

21. P. Zu, Z. K. Tang, G. K. L. Wong, M. Kawasaki, A. Ohtomo, H. Koinuma, and Y. Segawa, “Ultraviolet spontaneous and stimulated emissions from ZnO microcrystallite thin films at room temperature,” Solid State Commun. **103**, 459–463 (1997). [CrossRef]

**k**= 2.5 × 10

^{5}cm

^{−1}was estimated. Δ

**k**

_{m}= 7.0×10

^{5}cm

^{−1}for 6T was also obtained by using the level spacing between the ground and the first excited state of the Landau levels. However, this value can be further reduced when Coulomb interactions are considered. In the case of the weak-field regime, the magnetically-induced confinement effect is likely to be suppressed due to thermal effects, but a reduction in the density of states might be expected as the arrayed points in k-space merge into the rings.

*τ*

_{r}(

*T*) in the presence of a flux density of 6T increases with temperature as

*τ*

_{r}(

*T*) ∼

*T*

^{1.3}. Although the power order 1.3 may not represent the presence of an intermediate dimension, the power order of the temperature-dependent radiative decay time can be used to evaluate the nature of the effective confinement. On the other hand, when the magnetic length (

*a*

_{B}), it is also known that the oscillator strength of electron-hole pair becomes enhanced as the magnetic field increases due to shrinkage of the wavefunction of the relative motion of the electron and hole in the magnetic field. As a result, the radiative decay time decreases. We have estimated that the magnetic length (

*L*= 10.4nm) at 6T is still larger than

*a*

_{B}∼ 1.8nm in ZnO, which confirms again the weak-field regime. Therefore, the relative decrease of the radiative decay time at 6T compared to that in the absence of a magnetic field may not be dominated by the wavefunction shrinkage effect [22

22. J. D. Berger, O. Lyngnes, H. M. Gibbs, G. Khitrova, T. R. Nelson, E. K. Lindmark, A. V. Kavokin, M. A. Kaliteevski, and V. V. Zapasskii, “Magnetic-field enhancement of the exciton-polariton splitting in a semiconductor quantum-well microcavity: The strong coupling threshold,” Phys. Revs. B **54**, 1975–1981 (1996). [CrossRef]

*h̄ω*

_{c}∼ 4.4meV), the diamagnetic perturbation energy of the center-of-mass exciton (

*M*

_{⊥}is the total FX mass in the plane perpendicular to external field (

*Bẑ*) corresponding to the vector potential

*r*,

*θ*). The first-order perturbation of the diamagnetic effect is always of positive value (

*ε*

^{(1)}> 0), but the second-order perturbation energy for the ground state can be negative (

*ε*

^{(2)}< 0) in particular conditions. It is noticeable that the second-order perturbation for the excited states are also of positive value. In the case of a quantum well, the negative

*ε*

^{(2)}occurs only when the state filling from the ground state is extended beyond a half of the energy between the ground state and the first excited state. Therefore, the redshift under 6T in Fig. 1(c) is possibly a consequence of the two competing terms (

*δε*(

*B*) ≃

*ε*

^{(1)}+

*ε*

^{(2)}< 0), where

*ε*

^{(2)}is more pronounced than

*ε*

^{(1)}. It was known that ZnO is intrinsically n-type without intentional doping due to zinc interstitials, oxygen vacancies, and hydrogen. As the doping density is high (10

^{17}∼ 10

^{18}cm

^{−3}), the negative

*ε*

^{(2)}in our ZnO nanorods is possibly associated with state filling (or the Fermi level), which is similar to the case of a doped quantum well. However, further work is necessary to uncover the origin of the negative

*ε*

^{(2)}, which is not clear at the moment. Nevertheless, when

*ε*

^{(2)}is negative, it is also known that the effective mass in the plane perpendicular to magnetic field becomes heavier (

8. F. V. Kyrychenko, Y. D. Jho, J. Kono, S. A. Cooker, G. D. Sanders, D. H. Reitze, C. J. Stanton, X. Wei, C. Kadow, and A. C. Gossard, “Interband magnetoabsorption study of the shift of the Fermi energy of a 2DEG with an in-plane magnetic field,” Phisica E **22**, 624–627 (2004). [CrossRef]

*k*

_{0}decrease. These effects may explain why the power order of the temperature-dependent radiative decay time has decreased (

*τ*

_{r}(

*T*) ∼

*T*

^{1.3}) in the presence of a weak external magnetic field (6T) when compared to the bulk nature in the absence of a magnetic field (

*τ*

_{r}(

*T*) ∼

*T*

^{1.5}). Intuitively, the induced anisotropy of effective mass seems to change the confinement dimensionality effectively, i.e., the heavier effective mass in the plane perpendicular to the magnetic field affects transport, by which the lateral confinement effect is enhanced although the weak magnetic field is not enough to induce a one-dimensional nature.

## 4. Conclusion

*τ*

_{r}∼

*T*

^{1.5}) at low temperatures (< 40K), whereby the alternative method of temperature-dependent decay time for determining dimensionality has been verified. In the weak magnetic field regime for ZnO (6T), a significant decrease in the power order of the temperature dependence of the radiative decay time (∼

*T*

^{1.3}) was attributed to an enhancement of the effective mass perpendicular to the magnetic field and a redshift of the center-of-mass exciton as a consequence of perturbation effects in the weak-field regime.

## Acknowledgments

## References and links

1. | Zhong Lin Wang, “Zinc oxide nanostructures: growth, properties and applications,” J. Phys.: Condens. Matter |

2. | Mark Fox, |

3. | S. Schimitt-Rink, J. B. Stark, W. H. Knox, D. S. Chemla, and W. Schäfer, “Optical properties of quasi-zero-dimensional magneto-excitons,” Appl. Phys. A |

4. | Y. D. Jho, Xiaoming Wang, J. Kono, D. H. Reitze, X. Wei, A. A. Belyanin, V. V. Kocharovsky, Vl. V. Kocharovsky, and G. S. Solomon, “Cooperative Recombination of a Quantized High-Density Electron-Hole Plasma in Semiconductor Quantum Wells,” Phys. Rev. Lett. |

5. | Claus F. Klingshirn, |

6. | G. W. ’t Hooft, W. A. J. A. van der Poel, L. W. Molenkamp, and C. T. Foxon, “Giant oscillator strength of free excitons in GaAs,” Phys. Rev. B |

7. | H. Akiyama, S. Koshiba, T. Someya, K. Wada, H. Noge, Y. Nakamura, T. Inoshita, and A. Shimizu, “Thermalization Effect on Radiative Decay of Exciton in Quantum Wires,” Phys. Rev. Lett. |

8. | F. V. Kyrychenko, Y. D. Jho, J. Kono, S. A. Cooker, G. D. Sanders, D. H. Reitze, C. J. Stanton, X. Wei, C. Kadow, and A. C. Gossard, “Interband magnetoabsorption study of the shift of the Fermi energy of a 2DEG with an in-plane magnetic field,” Phisica E |

9. | Wei Geng, Sergei Kostcheev, Corinne Sartel, Vincent Sallet, Michael Molinari, Olivier Simonetti, Gilles Lérondel, Louis Giraudet, and Christophe Couteau, “Ohmic contact on single ZnO nanowires grown by MOCVD,” Phys. Status Solidi C. |

10. | X. H. Zhang, S. J. Chua, A. M. Yong, H. Y. Yang, S. P. Lau, S. F. Yu, X. W. Sun, Lei Miao, Masaki Tanemura, and Sakae Tanemura, “Exciton radiative lifetime in ZnO nanorods fabricated by vapor phase transport method,” Appl. Phys. Lett. |

11. | Fang-Yi Jen, Yen-Cheng Lu, Cheng-Yen Chen, Hsiang-Chen Wang, C. C. Yang, Bao-ping Zhang, and Yusaburo Segawa, “Temperature-dependent exciton dynamics in a ZnO thin film,” Appl. Phys. Lett. |

12. | Cheol Hyoun, Ahn Sanjay, Kumar Mohanta, Nae Eung Lee, and Hyung Koun Cho, “Enhanced exciton-phonon interactions in photoluminescence of ZnO nanopencils,” Appl. Phys. Lett. |

13. | Walter R. L. Lambrecht, Anna V. Rodina, Sukit Limpijumnong, B. Segall, and Bruno K. Meyer, “Valence-band ordering and magneto-optic exciton fine structure in ZnO,” Phys. Rev. B |

14. | S. J. Pearton, D. P. Norton, K. Ip, Y. W. Heo, and T. Steiner, “Recent advances in processing of ZnO,” J. Vac. Sci. Technol. B |

15. | Brendan Enright and Donald Fizmaurice, “Spectroscopic Determination of Electron and Hole Effective Masses in a Nanocrystalline Semiconductor Film,” J. Phys. Chem. |

16. | R. C. Miller, D. A. Kleinman, W. A. Nordland Jr., and A. C. Gossard, “Luminescence studies of optically pumped quantum wells in GaAs-Al |

17. | D. Takamizu, Y. Nishimoto, S. Akasaka, H. Yuji, K. Tamura, K. Nakahara, T. Onuma, T. Tanabe, H. Takasu, M. Kawasaki, and S. F. Chichibu, “Direct correlation between the internal quantum efficiency and photoluminescence lifetime in undoped ZnO epilayers grown on Zn-polar ZnO substrates by plasma-assisted molecular beam epitaxy,” J. Appl. Phys. |

18. | W. I. Park, Y. H. Jun, S. W. Jung, and Gyu-Chul Yi, “Excitonic emissions observed in ZnO single crystal nanorods,” Appl. Phys. Lett. |

19. | Richard L. Liboff, |

20. | Kerson Huang, |

21. | P. Zu, Z. K. Tang, G. K. L. Wong, M. Kawasaki, A. Ohtomo, H. Koinuma, and Y. Segawa, “Ultraviolet spontaneous and stimulated emissions from ZnO microcrystallite thin films at room temperature,” Solid State Commun. |

22. | J. D. Berger, O. Lyngnes, H. M. Gibbs, G. Khitrova, T. R. Nelson, E. K. Lindmark, A. V. Kavokin, M. A. Kaliteevski, and V. V. Zapasskii, “Magnetic-field enhancement of the exciton-polariton splitting in a semiconductor quantum-well microcavity: The strong coupling threshold,” Phys. Revs. B |

**OCIS Codes**

(160.3820) Materials : Magneto-optical materials

(160.6000) Materials : Semiconductor materials

(250.5230) Optoelectronics : Photoluminescence

(300.6500) Spectroscopy : Spectroscopy, time-resolved

**ToC Category:**

Materials

**History**

Original Manuscript: May 6, 2014

Revised Manuscript: July 9, 2014

Manuscript Accepted: July 9, 2014

Published: July 17, 2014

**Citation**

W. Lee, T. Kiba, A. Murayama, C. Sartel, V. Sallet, I. Kim, R. A. Taylor, Y. D. Jho, and K. Kyhm, "Temperature dependence of the radiative recombination time in ZnO nanorods under an external magnetic field of 6T," Opt. Express **22**, 17959-17967 (2014)

http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-22-15-17959

Sort: Year | Journal | Reset

### References

- Zhong Lin Wang, “Zinc oxide nanostructures: growth, properties and applications,” J. Phys.: Condens. Matter16, R829–R858 (2004).
- Mark Fox, Optical Properties of Solids, 2nd Edition (OXFORD University Press, 2010).
- S. Schimitt-Rink, J. B. Stark, W. H. Knox, D. S. Chemla, and W. Schäfer, “Optical properties of quasi-zero-dimensional magneto-excitons,” Appl. Phys. A53, 491–502 (1991). [CrossRef]
- Y. D. Jho, Xiaoming Wang, J. Kono, D. H. Reitze, X. Wei, A. A. Belyanin, V. V. Kocharovsky, Vl. V. Kocharovsky, and G. S. Solomon, “Cooperative Recombination of a Quantized High-Density Electron-Hole Plasma in Semiconductor Quantum Wells,” Phys. Rev. Lett.96, 237401 (2006). [CrossRef] [PubMed]
- Claus F. Klingshirn, Semiconductor Optics, 4th Edition (Springer, 2012). [CrossRef]
- G. W. ’t Hooft, W. A. J. A. van der Poel, L. W. Molenkamp, and C. T. Foxon, “Giant oscillator strength of free excitons in GaAs,” Phys. Rev. B35, 8281–8284 (1987). [CrossRef]
- H. Akiyama, S. Koshiba, T. Someya, K. Wada, H. Noge, Y. Nakamura, T. Inoshita, and A. Shimizu, “Thermalization Effect on Radiative Decay of Exciton in Quantum Wires,” Phys. Rev. Lett.72, 924–927 (1994). [CrossRef] [PubMed]
- F. V. Kyrychenko, Y. D. Jho, J. Kono, S. A. Cooker, G. D. Sanders, D. H. Reitze, C. J. Stanton, X. Wei, C. Kadow, and A. C. Gossard, “Interband magnetoabsorption study of the shift of the Fermi energy of a 2DEG with an in-plane magnetic field,” Phisica E22, 624–627 (2004). [CrossRef]
- Wei Geng, Sergei Kostcheev, Corinne Sartel, Vincent Sallet, Michael Molinari, Olivier Simonetti, Gilles Lérondel, Louis Giraudet, and Christophe Couteau, “Ohmic contact on single ZnO nanowires grown by MOCVD,” Phys. Status Solidi C.10, 1292–1296 (2013).
- X. H. Zhang, S. J. Chua, A. M. Yong, H. Y. Yang, S. P. Lau, S. F. Yu, X. W. Sun, Lei Miao, Masaki Tanemura, and Sakae Tanemura, “Exciton radiative lifetime in ZnO nanorods fabricated by vapor phase transport method,” Appl. Phys. Lett.90, 013107 (2007). [CrossRef]
- Fang-Yi Jen, Yen-Cheng Lu, Cheng-Yen Chen, Hsiang-Chen Wang, C. C. Yang, Bao-ping Zhang, and Yusaburo Segawa, “Temperature-dependent exciton dynamics in a ZnO thin film,” Appl. Phys. Lett.87, 252117 (2005). [CrossRef]
- Cheol Hyoun, Ahn Sanjay, Kumar Mohanta, Nae Eung Lee, and Hyung Koun Cho, “Enhanced exciton-phonon interactions in photoluminescence of ZnO nanopencils,” Appl. Phys. Lett.94, 269104 (2009).
- Walter R. L. Lambrecht, Anna V. Rodina, Sukit Limpijumnong, B. Segall, and Bruno K. Meyer, “Valence-band ordering and magneto-optic exciton fine structure in ZnO,” Phys. Rev. B65, 075207 (2002). [CrossRef]
- S. J. Pearton, D. P. Norton, K. Ip, Y. W. Heo, and T. Steiner, “Recent advances in processing of ZnO,” J. Vac. Sci. Technol. B22, 932–948 (2004). [CrossRef]
- Brendan Enright and Donald Fizmaurice, “Spectroscopic Determination of Electron and Hole Effective Masses in a Nanocrystalline Semiconductor Film,” J. Phys. Chem.100, 1027–1035 (1996). [CrossRef]
- R. C. Miller, D. A. Kleinman, W. A. Nordland, and A. C. Gossard, “Luminescence studies of optically pumped quantum wells in GaAs-AlxGa1−xAs multilayer structures,” Phys. Rev. B22, 863–871 (1980). [CrossRef]
- D. Takamizu, Y. Nishimoto, S. Akasaka, H. Yuji, K. Tamura, K. Nakahara, T. Onuma, T. Tanabe, H. Takasu, M. Kawasaki, and S. F. Chichibu, “Direct correlation between the internal quantum efficiency and photoluminescence lifetime in undoped ZnO epilayers grown on Zn-polar ZnO substrates by plasma-assisted molecular beam epitaxy,” J. Appl. Phys.103, 063502 (2008). [CrossRef]
- W. I. Park, Y. H. Jun, S. W. Jung, and Gyu-Chul Yi, “Excitonic emissions observed in ZnO single crystal nanorods,” Appl. Phys. Lett.82, 964–966 (2003). [CrossRef]
- Richard L. Liboff, Introductory Quantum Mechanics, 4th Edition (Addison - Wesley, 2003).
- Kerson Huang, Statistical Mechanics, 2nd Edition (John Wiley & Sons, 1987).
- P. Zu, Z. K. Tang, G. K. L. Wong, M. Kawasaki, A. Ohtomo, H. Koinuma, and Y. Segawa, “Ultraviolet spontaneous and stimulated emissions from ZnO microcrystallite thin films at room temperature,” Solid State Commun.103, 459–463 (1997). [CrossRef]
- J. D. Berger, O. Lyngnes, H. M. Gibbs, G. Khitrova, T. R. Nelson, E. K. Lindmark, A. V. Kavokin, M. A. Kaliteevski, and V. V. Zapasskii, “Magnetic-field enhancement of the exciton-polariton splitting in a semiconductor quantum-well microcavity: The strong coupling threshold,” Phys. Revs. B54, 1975–1981 (1996). [CrossRef]

## 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.

« Previous Article | Next Article »

OSA is a member of CrossRef.