III–V-on-Si Midwave Infrared Photodetectors with High Operating Temperature

By taking advantage of interfacial misfit arrays and carefully engineering parameters during molecular beam epitaxy, we report the growth of GaSb-on-Si(001) virtual substrates whose structural properties rival the current state-of-the-art, while maintaining a total epitaxial thickness of ≤3 μm. To demonstrate the value of these virtual substrates, we have integrated them with nBn photodetectors composed of InAs/InAsSb-strained layer superlattices. The resulting devices exhibit low noise and background limited infrared photodetection at temperatures as high as 160 K, with sufficient quality for use in thermal imaging. This work advances ongoing Si photonics efforts, particularly for low cost, large-area focal plane arrays with high operating temperatures.