Graphene – Narrow Bandgap Semiconductor Heterostructures for Mid-Infrared Photodetection*

Graphene-based semiconductor heterostructures have attracted attention for realizing optoelectronic devices, especially for photodetection from the deep-UV to the mid-infrared region. These photodetectors utilize graphene as a photoconductive channel to circulate photocurrent, fabricated on top of a narrow semiconductor substrate that will use a phenomenon known as photogating to obtain a high photoconductive gain. While a common material used in the substrate is silicon (Si), indium antimonide (InSb) offers a promising substitute, as it has a direct and narrow bandgap semiconductor. These detectors show high photo-response to the mid-infrared incident light at the wavelength of 10 µm. The work provides a method for achieving high-performance optoelectronics operating in the mid-infrared region at room temperature.