High-responsivity InAs quantum well photo-FET integrated on Si substrates for extended-range short-wave infrared photodetector applications

Abstract

Low-intensity light detection necessitates high-responsivity photodetectors. To achieve this, we report In0.53Ga0.47As/InAs/In0.53Ga0.47As quantum well (InAs QW) photo-field-effect-transistors (photo-FETs) integrated on a Si substrate using direct wafer bonding. Structure of the InAs QW channel was carefully designed to achieve higher effective mobility and a narrower bandgap compared with a bulk In0.53Ga0.47As, while suppressing the generation of defects due to lattice relaxations. High-performance 2.6 nm InAs QW photo-FETs were successfully demonstrated with a high on/off ratio of 105 and a high effective mobility of 2370 cm2/(V·s). The outstanding transport characteristics in the InAs QW channel result in an optical responsivity 1.8 times greater than InGaAs photo-FETs and the fast rising/falling times. Further, we experimentally confirmed that the InAs QW photo-FET can detect light in the short-wavelength infrared (SWIR; 1.0–2.5 μm) near 2 μm thanks to bandgap engineering through InAs QW structures. Our result suggests that the InAs QW photo-FET is promising for high-responsivity and extended-range SWIR photodetector applications.