Time-resolved photoluminescence spectroscopy of InGaN multiple quantum wells

  • Lee, Joo-In (Optoelectronics Laboratory, Korea Research Institute of Standards and Science) ;
  • Shin, Eun-joo (Optoelectronics Laboratory, Korea Research Institute of Standards and Science) ;
  • Lee, J.Y. m (Thin Film Laboratory, Korea Research Institute of Standards and Science) ;
  • Kim, S.T. (Department of Physics, Chungbuk National University) ;
  • G.S. Lim (Department of Physics, Chungbuk National University) ;
  • Lee, H.G. (School of Electrical and Electronic Engineering, Chungbuk National University,)
  • Published : 2000.03.01

Abstract

We have fabricated by metal organic chemical vapor deposition (MOCVD) In$\_$0.13/Ga$\_$0.87/N/GaN multiple quantum well (MQW) with thickness as thin as 10 A and barriers also of th same width on (0001) sapphire substrate. We have investigated this thin MQW by steady-state and time-resolved photoluminescence(PL) in picosecond time scale in a wide temperature range from 10 to 290 K. In the PL at 10 K, we observed a broad peak at 3.134 eV which was attributed to the quantum well emission of InGaN. The full width at half maximum (FWHM) of this peak was 129 meV at 10 K and its broadening at low temperatures was considered to be due to compositional fluctuations and interfacial disorder in the alloy. The narrow width of the quantum well was mainly responsible for the broadening of the emission linewidth. We also observed an intense and sharp peak at 3.471 eV of GaN barrier. From the temperature dependent PL measurements, the activation energy of the InGaN quantum well emision peak was estimated to be 69 meV. The lifetime of the quantum well emission was found to be 720 ps at 10 K, which was explained in terms of the exciton localization arising from potential fluctuations.

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