We report electron-beam-induced current (EBIC) microscopy carried out on free-standing GaAs nanowire core–shell, p–n tunnel junctions. The carrier kinetics in both the n-type core and the p-type shell were determined by analyzing radial EBIC profiles as a function of beam energy. These profiles are highly sensitive to geometric effects such as facet width, shell and core thicknesses, and depletion widths. Combined with Monte Carlo simulations, they permitted measurement of the minority carrier diffusion lengths in the core and the shell, as well as the depletion widths as a function of radial direction. The relatively short minority carrier diffusion length in the core (50 nm), can be attributed to bulk point defects originating from low-temperature core growth (400 ^∘C), or to interfacial recombination at traps at the p–n junction.

我们报告了在自立式 GaAs 纳米线核-壳、p-n 隧道结上进行的电子束感应电流 (EBIC) 显微镜检查。n 型核和 p 型壳中的载流子动力学是通过分析作为束能量函数的径向 EBIC 分布来确定的。这些剖面对几何效应高度敏感，例如小平面宽度、壳和核厚度以及耗尽宽度。结合蒙特卡罗模拟，他们允许测量核和壳中的少数载流子扩散长度，以及作为径向函数的耗尽宽度。核心中相对较短的少数载流子扩散长度 (50 nm)，可归因于源自低温核心生长 (400 ^∘C)，或在 p-n 结处的陷阱处进行界面复合。