Studies of electro-optical properties and band alignment of InGaPN/GaAs heterostructures by photoreflectance and photoluminescence

K. I. Lin, K. C. Chen, T. S. Wang, Yan-Ten Lu, J. S. Hwang

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2 Citations (Scopus)

Abstract

Photoreflectance (PR) and photoluminescence (PL) spectra are measured for a series of In 0.54 Ga 0.46 P 1-y N y /GaAs heterostructures at temperatures ranging from 25 to 300 K. The redshifts of the PR and PL peaks indicate that the band gap of InGaPN is dramatically reduced as nitrogen is incorporated. The transition energies of the band edge at various temperatures are measured and least-squares fitted to the Varshni equation. With N incorporation, the PL peak energy exhibits a particular behavior with temperature, which is not observed in PR spectra. This is attributed to carrier localization at low temperatures resulting from N clusters in the samples. In addition, the emergence of additional peaks in PR spectra as N is incorporated implies that the band alignment switches from type I to type II, due to the lowering of the conduction band, thus forming a two-dimensional electron gas (2DEG) in the interface region between InGaPN and GaAs. The number of confined levels in the 2DEG is found to increase with N concentrations.

Original languageEnglish
Pages (from-to)211-214
Number of pages4
JournalPhysica E: Low-Dimensional Systems and Nanostructures
Volume32
Issue number1-2 SPEC. ISS.
DOIs
Publication statusPublished - 2006 May 1

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics

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