A Short-Wave Infrared Nanoinjection Imager With 2500 A/W Responsivity and Low Excess Noise

We report on a novel nanoinjection-based short-wave infrared imager, which consists of InGaAs/GaAsSb/InAlAs/InP-based nanoinjection detectors with internal gain. The imager is 320×256 pixels with a 30-m pixel pitch. The test pixels show responsivity values in excess of 2500 A/W, indicating generation of more than 2000 electrons/photon with high quantum efficiency. This amplification is achieved at complementary metal-oxide semiconductor (CMOS) compatible, subvolt bias. The measured excess noise factor F of the hybridized imager pixels is around 1.5 at the responsivity range 1500 to 2000 A/W. The temperature behavior of the internal dark current of the imager pixels is also studied from 300 to 77 K. The presented results show, for the first time, that the nanoinjection mechanism can be implemented in imagers to provide detector-level internal amplification, while maintaining low noise levels and CMOS compatibility.