To avoid the trap-induced, low-frequency internal gain and improve the reliability for thermal storage test, a novel structure of GaAs metal-semiconductor-metal photodetector with InGaP buffer and capping layers is investigated, The dark current density of the photodetectors is about 7 mu A/cm(2) Its responsivity at 0.83-mu m wavelength is about 0.48 A/W. After thermal storage at 150 degrees C for 10 h, no performance degradation was found in the novel photodetectors.
