Ramaswamy Priyanka, Devkota Shisir, Pokharel Rabin, Nalamati Surya, Stevie Fred, Jones Keith, Reynolds Lew, Iyer Shanthi
Department of Electrical and Computer Engineering, North Carolina A&T State University, Greensboro, NC, 27401, USA.
Nanoengineering, Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro, NC, 27401, USA.
Sci Rep. 2021 Apr 15;11(1):8329. doi: 10.1038/s41598-021-87825-4.
We report the first study on doping assessment in Te-doped GaAsSb nanowires (NWs) with variation in Gallium Telluride (GaTe) cell temperature, using X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), conductive-atomic force microscopy (C-AFM), and scanning Kelvin probe microscopy (SKPM). The NWs were grown using Ga-assisted molecular beam epitaxy with a GaTe captive source as the dopant cell. Te-incorporation in the NWs was associated with a positive shift in the binding energy of the 3d shells of the core constituent elements in doped NWs in the XPS spectra, a lowering of the work function in doped NWs relative to undoped ones from UPS spectra, a significantly higher photoresponse in C-AFM and an increase in surface potential of doped NWs observed in SKPM relative to undoped ones. The carrier concentration of Te-doped GaAsSb NWs determined from UPS spectra are found to be consistent with the values obtained from simulated I-V characteristics. Thus, these surface analytical tools, XPS/UPS and C-AFM/SKPM, that do not require any sample preparation are found to be powerful characterization techniques to analyze the dopant incorporation and carrier density in homogeneously doped NWs.
我们报告了第一项关于碲掺杂的砷化镓锑纳米线（NWs）中掺杂评估的研究，该研究通过改变碲化镓（GaTe）电池温度，使用X射线光电子能谱（XPS）、紫外光电子能谱（UPS）、导电原子力显微镜（C-AFM）和扫描开尔文探针显微镜（SKPM）进行。NWs采用镓辅助分子束外延生长，以GaTe俘获源作为掺杂剂电池。NWs中碲的掺入与XPS光谱中掺杂NWs核心组成元素3d壳层结合能的正向移动、UPS光谱中掺杂NWs相对于未掺杂NWs功函数的降低、C-AFM中显著更高的光响应以及SKPM中观察到的掺杂NWs相对于未掺杂NWs表面电位的增加有关。从UPS光谱确定的碲掺杂砷化镓锑NWs的载流子浓度与从模拟I-V特性获得的值一致。因此，这些无需任何样品制备的表面分析工具，即XPS/UPS和C-AFM/SKPM，被发现是分析均匀掺杂NWs中掺杂剂掺入和载流子密度的强大表征技术。
