[TuP3D] D. Photonic devices and related technologies

[TuP3D-04] Origin of low dark current operation of InAs/GaAs(111)A infrared detectors: Effects of residual impurities on GaAs substrates

〇Takaaki Mano¹, Nobuyuki Ishida¹, Takuya Kawazu¹, Akihiro Ohtake¹, Hideki T. Miyazaki¹ (1. National Institute for Materials Science (NIMS) (Japan))

Infrared detectors are indispensable optical devices that support the safety and security of modern society. Recently, we have reported a new type of infrared detector based on metamorphic InAs/GaAs(111)A heterostructure. While very low-dark current operation were demonstrated at low temperatures, the operation principles have not yet been clear. Here, we report on the effect of Fermi-level pinning caused by the residual impurities of initial surface of GaAs substrates. The pinning effect causes a steep band rise at the undoped-GaAs/n-GaAs interface that remains unchanged even under high applied bias, thereby allowing the achievement of low dark current.