1.3-μm P-I-N Photodetector using GaAs with As Precipitates (Gaas:As)

We report the successful fabrication of the first GaAs detector which operates in the 1.3- to 1.5-μm optical range. The detector is a P-i-N photodiode with an intrinsic layer composed of undoped GaAs which was grown at 225°C and subsequently annealed at 600°C. This growth process has been demonstrated to produce a high density of As precipitates in the low-temperature grown region, which we show here to exhibit absorption through internal photoemission. The internal Schottky barrier height of the As precipitates is found to be 0.7 eV, leading to reasonable room-temperature responsivity out to around 1.7 μm. © 1991 IEEE