We have studied the persistent photoconductivity (PPC) effect in Ga 0.49 In0.51 P/GaAs heterostructures. Through time- and temperature-dependent Hall effect, we observe very small relaxation rates and the PPC remains observable at room temperature. Optical experiments show an optical energy threshold of 1.15 eV and an infrared quenching of the PPC. Thermal cycling of the samples strongly affects the PPC and the quenching temperature. The center responsible for the observed PPC, therefore, appears related to defects. Most of our observations are qualitatively understood in a large lattice relaxation DX-like center approach. However, the origin of the high quenching temperature remains to be explained.
ASJC Scopus subject areas
- Physics and Astronomy(all)