Suppression of surface leakage in gate controlled type-II InAs/GaSb mid-infrared photodetectors

摘要: One of the biggest challenges improving electrical performance in Type II InAs/GaSb superlattice photodetector is suppressing surface leakage. Surface leakage screens important bulk dark current mechanisms, and brings difficulty and uncertainty to material optimization intrinsic parameters extraction such as carrier lifetime mobility. Most treatments were attempted beyond mid-infrared (MWIR) regime because compared performance, MWIR was generally considered be a minor factor. In this work, we show that below 150K, still strongly affects very high p-π-M-n photon detectors. With gating technique, can effectively eliminate the surface controllable manner. At 110K, density 4.7 μm cut-off gated diode is more than 2 orders magnitude lower SiO2 passivated ungated diode. quantum efficiency 48%, specific detecivity diodes attains 2.5 x 1014 cmHz1/2/W, which 3.6 times higher than that diodes.