Controlling the shell microstructure in a low-temperature-grown SiNWs and correlating it to the performance of the SiNWs-based micro-supercapacitor

Abstract

We report here the effect of a controlled modification of the shell microstructure around the crystalline core of a silicon nanowire (SiNW) grown at a low (320 °C) temperature by the hot wire chemical vapor processing (HWCVP) method. We demonstrate these effects through the evaluation of the performance of a micro-supercapacitor (µ-SC) device fabricated with these SiNWs having different shell structures. It is to be emphasized that the shell microstructure could be modified through a controlled interplay of the process parameters during the growth. A careful optimization of the shell microstructure in these nanowires during its low-temperature deposition has led to a µ-SC with capacitance value of 94 µF/cm2. This result opens up exciting opportunities for HWCVP-grown SiNWs to be employed for on-chip µ-SC and other low-temperature applications.