Branched HgTe Nanorods for Stable Room Temperature Extended Short-Wave Infrared Photodetectors

Single-element detectors (SEDs) with a room temperature extended short-wave infrared (eSWIR) photoresponse were fabricated with branched nanorods of HgTe. Nanorods with high aspect (length/width) ratios were obtained by using stoichiometric excesses of Hg (i.e., [Hg]/[Te] molar ratios greater than one) and relatively low reaction temperatures, as low as room temperature. The size-tunable optical cutoff wavelengths of the detectors ranged from 2 to 3.5 μm, with specific detectivities as high as 2.4 × 10¹¹ Jones. The devices retained their responsivity for more than a year. Branched nanorods of HgTe are promising materials for IR photodetectors and imagers.