Research On Photoelectric Converter Device Based On Kinked InP Nanowire Array

Semiconductor nanowires have become one of the ideal structures for the new generation of optoelectronic devices due to their unique structural characteristics and novel optical and electrical properties.Due to its excellent anti reflection ability,nanowire arrays with uniform diameter and regular arrangement perpendicular to the substrate have shown great application potential in solar cells and photodetectors.However,recent studies have shown that the light absorption of the above nanowire array structures has certain limitations,and there is still a large space for optimization of the structure.In recent years,kinked nanowires have been successfully prepared experimentally.Compared to vertical nanowires,kinked nanowires have significant advantages in crystal quality and are expected to further improve their light absorption capacity.This article focuses on the design of kinked InP nanowire array photoelectric conversion devices,and key achievements and innovations are as follows:(1)We designed a kinked InP nanowire axial pin junction array solar cell and simulated its light absorption and photoelectric conversion characteristics.Studies have shown that compared to vertical nanowire arrays,kinked nanowire arrays significantly enhance optical absorption by increasing the incident optical path,stimulating more resonant modes,and reducing substrate absorption.They also increase the absorption of the intrinsic region by suppressing recombination losses in the top highly doped region.When the total length of the nanowire is 1-1.5μm,the photoelectric conversion efficiency of the kink structure is over 14%,significantly higher than that of the vertical structure.In addition,the effect of kinked angle on device performance was studied,and it was found that a moderate kinked angle is beneficial for achieving higher efficiency.(2)A kinked InP nanowire axial pin junction array photodetector was designed and simulated its spectral absorption and photoelectric conversion characteristics.The results show that compared to vertical nanowire arrays,kinked nanowire arrays can achieve broad spectral absorption under TM polarized light,and have significant enhancement effects in the 450-870 nm wavelength band.At an incident wavelength of 850 nm,the response of the kinked nanowire array photodetector is 486.3 mA/W,and the external quantum efficiency EQE is 71%,which is 20%higher than that of the vertical nano wire array.In addition,due to the highly asymmetric structure,kinked nanowire arrays are sensitive to incident light at different polarization angles,and have important application potential in polarization sensitive detector devices.