A study of photomodulated reflectance on staircase-like, n-doped GaAs/Al (x) Ga1-x As quantum well structures


Donmez Ö. , Nutku F. , Erol A. , Arikan C. M. , Ergun Y.

NANOSCALE RESEARCH LETTERS, vol.7, 2012 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 7
  • Publication Date: 2012
  • Doi Number: 10.1186/1556-276x-7-622
  • Title of Journal : NANOSCALE RESEARCH LETTERS

Abstract

In this study, photomodulated reflectance (PR) technique was employed on two different quantum well infrared photodetector (QWIP) structures, which consist of n-doped GaAs quantum wells (QWs) between undoped Al (x) Ga1-x As barriers with three different x compositions. Therefore, the barrier profile is in the form of a staircase-like barrier. The main difference between the two structures is the doping profile and the doping concentration of the QWs. PR spectra were taken at room temperature using a He-Ne laser as a modulation source and a broadband tungsten halogen lamp as a probe light. The PR spectra were analyzed using Aspnes' third derivative functional form.