Thin-absorber AlInAsSb APDs for low-noise and low-voltage e-SWIR photodetection

Physical Sciences Inc. and Prof. Seth Bank at the University of Texas Austin will develop thin-absorber avalanche photodiodes based on digital alloys of AlInAsSb for high-performance photodetection between 2.0 – 2.5 μm. The AlInAsSb quaternary alloy system allows for compositional grading throughout the device structure, enabling novel photodiode architectures inaccessible with other III-V alloy systems. Our team will grow, fabricate, and characterize both single pixels and pixel arrays of AlInAsSb avalanche photodiodes based on a thin-absorber architecture for dark current suppression. The thin-absorber architecture, combined with additional innovations in the avalanche multiplication region, will simultaneously enable low-voltage, high-gain, low-noise, and low dark current operation. Achievement of these objectives will enable integration with Si CMOS readout circuitry for low power-consumption digital infrared focal plane arrays.