Optical properties of GaInNAs/GaAs quantum wells: character of optical transitions and carrier localisation effect

Abstract

The set of Ga 0.59 In 0.41 N x As 1-x GaAs single quantum wells (SQWs) with high nitrogen content (up to 5.2%) has been investigated in photoreflectance (PR) and photoluminescence (PL) spectroscopies at low and room temperatures. Strong manifestation of the carrier localisation effect due to the increase in nitrogen content has been observed. The carrier localization at low temperatures leads to a large Stokes shift and a decrease of the efficiency of band bending modulation. The second phenomena causes a significant decrease of PR signal at low temperatures. In addition, the temperature induced shift of the energy band gap significantly depends on nitrogen content. We have observed that the shift between 10 and 300 K is 82, 73, 67, and 62 meV for the SQW with the nitrogen content of 0, 2.0, 3.2, and 5.2%, respectively.