High-performance graphene-enhanced HgCdTe photodetectors for uncooled extended infrared band sensing and imaging

Abstract

The development of a scalable, low cost, low power, and room temperature operating detector technology capable of high spatial resolution imaging over IR bands of interest can advance and extend space and satellite sensing capabilities such as remote sensing and earth observation. Conventional infrared (IR) band photodetectors based on HgCdTe material operating over short-wave infrared (SWIR), mid-wave infrared (MWIR), and/or long-wave infrared (LWIR) bands often require external cooling to achieve high performance IR sensing and imaging. By integrating bilayers of doped graphene to function as a high mobility channel to aid the recombination of photogenerated carriers, a graphene-enhanced IR photodetector with HgCdTe absorbing layer can be developed providing high performance uncooled detection over SWIR, MWIR, and LWIR (~1.3-14 m) bands. Development of the high-performance IR photodetector technology involves ptype doping of graphene bilayers deposited on Si/SiO2 with boron using a spin-on dopant (SOD) process, and then transfer of the doped bilayer graphene onto HgCdTe substrates. The graphene-enhanced HgCdTe SWIR/MWIR/LWIR band detectors were analyzed and characterized material and optoelectronically to demonstrate high performance IR detection at room temperature for advanced NASA Earth Science, defense, and commercial applications.