GaInAsSb异质结纳米柱阵列光电阴极对电场的响应机制

Abstract GaSb-based nanopillar arrays photocathodes are widely used in the field of solar energy and thermal photovoltaic systems due to their high quantum efficiency, low dark current and wide response band. However, difficulties in collecting lateral photocurrents have hindered their application. This study established two models—constant high sublayer and internal electric fields—the study elucidated the mechanisms by which E in affect the photoemission behavior of heterostructure nanopillars. Results showed that the E in2 promotes top emission from heterojunction nanopillars, while the E in1 governs lateral emission. External electric fields enhanced the collection of laterally emitted electrons, leading to an increase in the net efficiency of the cathode. Specifically, at a field strength of 1.5 V/μm, the net efficiency of GaInAsSb NPAs exceeded 11 %, which was 1.75 times higher than that without electric field. This electric field enhances the photoelectric properties of the cathode of the nanopillar array, which is applicable to all shapes of nanopillar structures. This study uses theoretical calculations to explain the influence of electric fields on the performance of NPAs, which provides guidance for the future research and application of high-performance antimonide based NPA photocathodes.