OSA's Digital Library

Journal of Display Technology

Journal of Display Technology


  • Vol. 10, Iss. 7 — Jul. 1, 2014
  • pp: 574–581

Hybrid Sensor and Display Pixel Circuits for Mobile Near-to-Eye Applications

Nikolas P. Papadopoulos, Czang-Ho Lee, and William S. Wong

Journal of Display Technology, Vol. 10, Issue 7, pp. 574-581 (2014)

View Full Text Article

Acrobat PDF (1737 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

  • Export Citation/Save Click for help


Hybrid sensor/display pixels and their operating schemes are proposed, simulated, and characterized. The circuit design implemented a phototransistor connected to a drive thin-film transistor (TFT) and an organic light-emitting diode (OLED). The circuits were fabricated using hydrogenated amorphous-silicon (a-Si:H) TFTs as a hybrid photosensor/switching device. The light sensitivity of the phototransistors and response to incident illumination were modeled and verified experimentally for different white-light intensities. The pixel gray scale was determined by the pulse-height voltage modulation from the phototransistor, which was varied by changing the light intensity. The resulting circuits have a wide dynamic range with a light to dark output current ratio of $10^{4}$ for TFTs having channel lengths of $<{{10}}\ \mu{m}$ and light intensity up to $\sim {{8}}\ {{mW/cm}}^{2}$ . A 256-RGB-level imaging scale is possible with 5-nA steps for each grey scale in a pixel array matrix having a refresh rate of more than 200 Hz.

© 2014 IEEE

Nikolas P. Papadopoulos, Czang-Ho Lee, and William S. Wong, "Hybrid Sensor and Display Pixel Circuits for Mobile Near-to-Eye Applications," J. Display Technol. 10, 574-581 (2014)

Sort:  Year  |  Journal  |  Reset


  1. L. E. Antonuk, J. M. Boudry, C. W. Kim, M. Longo, E. J. Morton, J. Yorkston, R. A. Street, "Signal, noise, and readout considerations in the development of amorphous silicon photodiode arrays for radiotherapy and diagnostic x-ray imaging," Proc. SPIE (1991) pp. 108.
  2. K. S. Karim, A. Nathan, J. A. Rowlands, "Amorphous silicon active pixel sensor readout circuit for digital imaging," IEEE Trans. Electron Devices 50, 200-208 (2003).
  3. N. P. Papadopoulos, A. A. Hatzopoulos, D. K. Papakostas, "An improved optical feedback pixel driver circuit," IEEE Trans. Electron Devices 56, 229-235 (2009).
  4. B. Richter, U. Vogel, R. Herold, K. Fehse, S. Brenner, L. Kroker, J. Baumgarten, "Bidirectional OLED microdisplay: Combining display and image sensor functionality into a monolithic CMOS chip," IEEE Int. Solid-State Circuits Conf. Dig. Tech. Papers pp. 314-316.
  5. T. Nishibe, H. Nakamura, "Value-added circuit and function integration for SOG (System-on Glass) based on LTPS technology," SID'06 Dig. (2006) pp. 1091.
  6. K. Mathieson, J. Loudin, G. Goetz, P. Huie, L. Wang, T. I. Kamins, L. Galambos, R. Smith, J. S. Harris, A. Sher, D. Palanker, "Photovoltaic retinal prosthesis with high pixel density," Nature Photon. 6, 391-397 (2012).
  7. H. S. Park, T. J. Ha, Y. Hong, M. K. Han, D. H. Woo, K. S. Shin, C. W. Kim, "A self-reset ambient-light sensor system for low-temperature polycrystalline-silicon active-matrix displays," J. Soc. Inf. Display 16, 889 (2008).
  8. S. H. Kim, S. H. Lee, W. H. Park, N. K. Son, A. R. Kim, J. H. Hur, J. H. Kwo, J. Jang, K. J. Im, D. Lee, D. S. Jeong, Y. G. Mo, H. K. Chung, "A 2 inch LTPS AMOLED with an embedded lateral p-i-n photodiode sensors," SID 08 Dig. pp. 724-727.
  9. A. V. Shah, H. Schade, M. Vanecek, J. Meier, E. Vallat-Sauvain, N. Wyrsch, U. Kroll, C. Droz, J. Bailat, "Thin-film Silicon Solar Cell Technology," Prog. Photovolt: Res. Appl. 12, 113-142 (2004).
  10. W. Ji, L. Zhang, M. Liu, J. Wang, G. Liu, W. Xie, H. Zhang, "High efficiency top-emitting white organic light-emitting devices with a (metal/organic)2 cathode," Current Appl. Phys. 11, 1410-1413 (2011).
  11. M. R. Esmaeili-Rad, N. P. Papadopoulos, M. Bauza, A. Nathan, W. S. Wong, "Blue light sensitive phototransistor for indirect X-ray image sensors," IEEE Electron Device Lett. 33, 567-569 (2012).
  12. N. P. Papadopoulos, M. Yang, M. R. Esmaeili-Rad, M. Sachdev, W. S. Wong, "Discussing pixel circuits for hybrid sensor and display pixel arrays," Proc. IDW/AD () pp. 325-328.
  13. M. R. Esmaeili-Rad, F. Li, A. Sazonov, A. Nathan, "Stability of nanocrystalline silicon bottom-gate thin film transistors with silicon nitride gate dielectric," J. Appl. Phys. 102, 064512-1-7 (2007) Also appeared in Virtual J. Nanoscale Sci. Technol., vol. 16, no. 16, 2007.
  14. N. P. Papadopoulos, A. A. Hatzopoulos, D. K. Papakostas, R. Picos, C. A. Dimitriadis, S. Siskos, "A light-impact model for p-type and n-type poly-Si TFTs," J. Display Technol. 5, 265-272 (2009).
  15. K. Ishihara, T. Tsuruma, Y. Iguchi, T. Sawada, M. Watanabe, Y. Maki, "Implementation of optical response of thin film transistor with verilog-a for mobile LCD applications," Proc. IEEE Int. Behavioral Modeling and Simulation Workshop (2008) pp. 39-44.
  16. F. Taghibakhsh, I. Khodami, K. S. Karim, "Characterization of short-wavelength-selective a-Si:H MSM photoconductors for large-area digital-imaging applications," IEEE Trans. Electron Devices 55, 337-342 (2008).
  17. K. Sakariya, A. Nathan, "Leakage and charge injection optimization in a-Si AMOLED displays," J. Display Technol. 2, 254-257 (2006).

Cited By

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.

CrossCheck Deposited