Decorrelation of the Light-emitting-Diode Internal-quantum-Efficiency Components - Studies of the Electron-hole Concentration-ratio at the Active-region Edge

Dinh Chuong Nguyen, David Vaufrey, Mathieu Leroux


GaN-based LEDs have emerged as a very promising white-light source since the last decade and become the main part of many applications. However, such applications usually require those LEDs to operate at their high-current regime, which unfortunately sees LED internal-quantum-efficiency dropping drastically. This so-called "IQE droop" has been related to different possible causes, among those the Auger recombination and the carrier leakage have recently been nominated as the most prominent ones. The quest for the droop's main cause has raised intense debate mostly because of incomplete knowledge about the wurzite GaN and difficulties in separately evaluating the effects of the droop-inducing-mechanisms. Hence, this PhD. work aims to separately study the IQE-droop interconnected components through new approaches. Simulation and characterization have both been carried out. In this paper, simulation results at the active-region edges of two different LED structures are presented. They suggest that carrier leakage play a major role in the LED efficiency droop and lead to further p-GaN-properties studies.


  1. Bertazzi, F., Goano, M., Zhou, X., Calciati, M., Ghione, G., Matsubara, M., Bellotti, E., 2013. Comment on “Direct Measurement of Auger Electrons Emitted from a Semiconductor Light-Emitting Diode under Electrical Injection: Identification of the Dominant Mechanism for Efficiency Droop” [Phys. Rev. Lett. 110, 177406 (2013)].
  2. Cabalu, J.S., Thomidis, C., Moustakas, T.D., Riyopoulos, S., Zhou, L., Smith, D.J., 2006. Enhanced internal quantum efficiency and light extraction efficiency from textured GaN/AlGaN quantum wells grown by molecular beam epitaxy. J. Appl. Phys. 99, 064904. doi:10.1063/1.2179120.
  3. Cao, X.A., Arthur, S.D., 2004. High-power and reliable operation of vertical light-emitting diodes on bulk GaN. Appl. Phys. Lett. 85, 3971. doi:10.1063/1.1810631.
  4. David, A., Grundmann, M.J., Kaeding, J.F., Gardner, N.F., Mihopoulos, T.G., Krames, M.R., 2008. Carrier distribution in (0001)InGaN/GaN multiple quantum well light-emitting diodes. Appl. Phys. Lett. 92, 053502. doi:10.1063/1.2839305.
  5. Delaney, K.T., Rinke, P., Van de Walle, C.G., 2009. Auger recombination rates in nitrides from first principles. Appl. Phys. Lett. 94, 191109. doi:10.1063/1.3133359.
  6. Della Sala, F., Di Carlo, A., Lugli, P., Bernardini, F., Fiorentini, V., Scholz, R., Jancu, J.-M., 1999. Freecarrier screening of polarization fields in wurtzite GaN/InGaN laser structures. Appl. Phys. Lett. 74, 2002. doi:10.1063/1.123727.
  7. Galler, B., Drechsel, P., Monnard, R., Rode, P., Stauss, P., Froehlich, S., Bergbauer, W., Binder, M., Sabathil, M., Hahn, B., Wagner, J., 2012. Influence of indium content and temperature on Auger-like recombination in InGaN quantum wells grown on (111) silicon substrates. Appl. Phys. Lett. 101, 131111. doi:10.1063/1.4754688.
  8. Hader, J., Moloney, J.V., Pasenow, B., Koch, S.W., Sabathil, M., Linder, N., Lutgen, S., 2008. On the importance of radiative and Auger losses in GaNbased quantum wells. Appl. Phys. Lett. 92, 261103. doi:10.1063/1.2953543.
  9. Hangleiter, A., Hitzel, F., Netzel, C., Fuhrmann, D., Rossow, U., Ade, G., Hinze, P., 2005. Suppression of Nonradiative Recombination by V-Shaped Pits in GaInN/GaN Quantum Wells Produces a Large Increase in the Light Emission Efficiency. Phys. Rev. Lett. 95. doi:10.1103/PhysRevLett.95.127402.
  10. Huang, S., Fan, B., Chen, Z., Zheng, Z., Luo, H., Wu, Z., Wang, G., Jiang, H., 2013. Lateral Current Spreading Effect on the Efficiency Droop in GaN Based LightEmitting Diodes. J. Disp. Technol. 9, 266-271. doi:10.1109/JDT.2012.2225092.
  11. Iveland, J., Martinelli, L., Peretti, J., Speck, J.S., Weisbuch, C., 2013. Direct Measurement of Auger Electrons Emitted from a Semiconductor LightEmitting Diode under Electrical Injection: Identification of the Dominant Mechanism for Efficiency Droop. Phys. Rev. Lett. 110. doi:10.1103/PhysRevLett.110.177406.
  12. Kim, H., Cho, J., Lee, J.W., Yoon, S., Kim, H., Sone, C., Park, Y., Seong, T.-Y., 2007. Measurements of current spreading length and design of GaN-based light emitting diodes. Appl. Phys. Lett. 90, 063510. doi:10.1063/1.2450670.
  13. Kim, M.-H., Schubert, M.F., Dai, Q., Kim, J.K., Schubert, E.F., Piprek, J., Park, Y., 2007. Origin of efficiency droop in GaN-based light-emitting diodes. Appl. Phys. Lett. 91, 183507. doi:10.1063/1.2800290.
  14. Kioupakis, E., Rinke, P., Delaney, K.T., Van de Walle, C.G., 2011. Indirect Auger recombination as a cause of efficiency droop in nitride light-emitting diodes. Appl. Phys. Lett. 98, 161107. doi:10.1063/1.3570656.
  15. Krames, M.R., Shchekin, O.B., Mueller-Mach, R., Mueller, G.O., Zhou, L., Harbers, G., Craford, M.G., 2007. Status and Future of High-Power Light-Emitting Diodes for Solid-State Lighting. J. Disp. Technol. 3, 160-175. doi:10.1109/JDT.2007.895339.
  16. Li, C.-K., Wu, Y.-R., 2012. Study on the Current Spreading Effect and Light Extraction Enhancement of Vertical GaN/InGaN LEDs. IEEE Trans. Electron Devices 59, 400-407. doi:10.1109/TED.2011.2176132.
  17. Morkoç, H., 2008. Handbook of nitride semiconductors and devices. Wiley-VCH?; John Wiley, distributor], Weinheim?: [Chichester.
  18. Mukai, T., Yamada, M., Nakamura, S., 1999. Characteristics of InGaN-Based UV/Blue/Green/Amber/Red Light-Emitting Diodes. Jpn. J. Appl. Phys. 38, 3976-3981. doi:10.1143/JJAP.38.3976.
  19. Ni, X., Fan, Q., Shimada, R., Özgür, U., Morkoç, H., 2008. Reduction of efficiency droop in InGaN light emitting diodes by coupled quantum wells. Appl. Phys. Lett. 93, 171113. doi:10.1063/1.3012388.
  20. Piprek, J., Farrell, R., DenBaars, S., Nakamura, S., 2006. Effects of built-in polarization on InGaN-GaN vertical-cavity surface-emitting lasers. IEEE Photonics Technol. Lett. 18, 7-9. doi:10.1109/LPT.2005.860045.
  21. Romanowski, Z., Kempisty, P., Sakowski, K., Str a¸k, P., Krukowski, S., 2010. Density Functional Theory (DFT) Simulations and Polarization Analysis of the Electric Field in InN/GaN Multiple Quantum Wells (MQWs). J. Phys. Chem. C 114, 14410-14416. doi:10.1021/jp104438y.
  22. Rozhansky, I.V., Zakheim, D.A., 2007. Analysis of processes limiting quantum efficiency of AlGaInN LEDs at high pumping. Phys. Status Solidi A 204, 227-230. doi:10.1002/pssa.200673567.
  23. Schubert, M.F., Chhajed, S., Kim, J.K., Schubert, E.F., Koleske, D.D., Crawford, M.H., Lee, S.R., Fischer, A.J., Thaler, G., Banas, M.A., 2007. Effect of dislocation density on efficiency droop in GaInN/GaN light-emitting diodes. Appl. Phys. Lett. 91, 231114. doi:10.1063/1.2822442.
  24. Schubert, M.F., Xu, J., Kim, J.K., Schubert, E.F., Kim, M.H., Yoon, S., Lee, S.M., Sone, C., Sakong, T., Park, Y., 2008. Polarization-matched GaInN/AlGaInN multi-quantum-well light-emitting diodes with reduced efficiency droop. Appl. Phys. Lett. 93, 041102. doi:10.1063/1.2963029.
  25. Son, J.H., Kim, B.J., Ryu, C.J., Song, Y.H., Lee, H.K., Choi, J.W., Lee, J.-L., 2012. Enhancement of wallplug efficiency in vertical InGaN/GaN LEDs by improved current spreading. Opt. Express 20, A287. doi:10.1364/OE.20.00A287.
  26. Thompson, G.H.B., 1980. Physics of semiconductor laser devices. J. Wiley, Chichester [Eng.]?; New York.
  27. Turin, V.O., 2005. A modified transferred-electron highfield mobility model for GaN devices simulation. Solid-State Electron. 49, 1678-1682. doi:10.1016/j.sse.2005.09.002.
  28. Xu, J., Schubert, M.F., Noemaun, A.N., Zhu, D., Kim, J.K., Schubert, E.F., Kim, M.H., Chung, H.J., Yoon, S., Sone, C., Park, Y., 2009. Reduction in efficiency droop, forward voltage, ideality factor, and wavelength shift in polarization-matched GaInN/GaInN multi-quantum-well light-emitting diodes. Appl. Phys. Lett. 94, 011113. doi:10.1063/1.3058687.
  29. Zhang, Z.-H., Ju, Z., Liu, W., Tan, S.T., Ji, Y., Kyaw, Z., Zhang, X., Hasanov, N., Sun, X.W., Demir, H.V., 2014. Improving hole injection efficiency by manipulating the hole transport mechanism through ptype electron blocking layer engineering. Opt. Lett. 39, 2483. doi:10.1364/OL.39.002483.

Paper Citation

in Harvard Style

Nguyen D., Vaufrey D. and Leroux M. (2015). Decorrelation of the Light-emitting-Diode Internal-quantum-Efficiency Components - Studies of the Electron-hole Concentration-ratio at the Active-region Edge . In Doctoral Consortium - DCPHOTOPTICS, (PHOTOPTICS 2015) ISBN , pages 37-46

in Bibtex Style

author={Dinh Chuong Nguyen and David Vaufrey and Mathieu Leroux},
title={Decorrelation of the Light-emitting-Diode Internal-quantum-Efficiency Components - Studies of the Electron-hole Concentration-ratio at the Active-region Edge},
booktitle={Doctoral Consortium - DCPHOTOPTICS, (PHOTOPTICS 2015)},

in EndNote Style

JO - Doctoral Consortium - DCPHOTOPTICS, (PHOTOPTICS 2015)
TI - Decorrelation of the Light-emitting-Diode Internal-quantum-Efficiency Components - Studies of the Electron-hole Concentration-ratio at the Active-region Edge
SN -
AU - Nguyen D.
AU - Vaufrey D.
AU - Leroux M.
PY - 2015
SP - 37
EP - 46
DO -