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

Low-intensity light detection necessitates high-responsivity photodetectors.To achieve this,we report In_(0.53)Ga_(0.47)As∕In As∕In_(0.53)Ga_(0.47)As quantum well(InAs QW)photo-field-effect-transistors(photo-FETs)integrated on a Si substrate using direct wafer bonding.Structure of the In As QW channel was carefully designed to achieve higher effective mobility and a narrower bandgap compared with a bulk In_(0.53)Ga_(0.47)As,while suppressing the generation of defects due to lattice relaxations.High-performance 2.6 nm In As QW photo-FETs were successfully demonstrated with a high on/off ratio of 10~5 and a high effective mobility of 2370 cm^(2)∕(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;1.0–2.5μm)near 2μm thanks to bandgap engineering through In As QW structures.Our result suggests that the InAs QW photo-FET is promising for high-responsivity and extended-range SWIR photodetector applications.

Directly modulated quantum dot lasers on silicon with a milliampere threshold and high temperature stability

Microring lasers feature ultralow thresholds and inherent wavelength-division multiplexing functionalities, offering an attractive approach to miniaturizing photonics in a compact area. Here, we present static and dynamic properties of microring quantum dot lasers grown directly on exact(001) GaP/Si. Effectively, a single-mode operation was observed at 1.3 μm with modes at spectrally distant locations. High temperature stability with T_0~103 K has been achieved with a low threshold of 3 mA for microrings with an outer ring radius of 15 μm and a ring waveguide width of 4 μm. Small signal modulation responses were measured for the first time for the microrings directly grown on silicon, and a 3 dB bandwidth of 6.5 GHz was achieved for a larger ring with an outer ring radius of 50 μm and a ring waveguide width of 4 μm. The directly modulated microring laser,monolithically integrated on a silicon substrate, can incur minimal real estate cost while offering full photonic functionality.