InGaN nanowire array photocathode with high electron harvesting capability

Abstract

With the rise of III-V semiconductor materials, InGaN materials began to be widely concerned. Nanowire arrays have excellent light trapping ability and generate a large number of photogenerated electrons. However, the adjacent nanowires will absorb these electrons twice, so the quantum efficiency cannot perfectly measure the emission performance of the nanowire array photocathode. We introduce the collection efficiency to evaluate the photoemission performance. It is based on this background that we study the photoemission performance of InGaN nanowire array under the assistance of height, incident light Angle and applied electric field. Finite-difference time-domain (FDTD) method is used to compare the quantum efficiency and collection efficiency of InGaN nanowire. We find that when the height of the nanowire is 600 nm, the angle of incident light is 65°, and the electric field strength is 0.6V/μm, InGaN nanowire arrays have the highest collection efficiency, with the collection efficiency up to 34% and the collection ratio up to 71%. The collection efficiency is 66% higher than that without external electric field. Therefore, the research in this paper can provide a theoretical reference for the preparation and performance improvement of InGaN nanowire array photocathode.