Comparative Study of Silicon Nanowires Grown From Ga, In, Sn, and Bi for Energy Harvesting

A high density of silicon nanowires for solar cell applications was fabricated on a single crystalline silicon wafer, using low eutectic temperature metal catalysts, namely, gallium, indium, tin, and bismuth. The use of silicon nanowires is exploited for light trapping with an aim to enhance the efficiency of solar cells. Additionally, we have optimized the deposition parameters so that there is merely deposition of amorphous silicon along with the growth of silicon nanowires. Thus, it may improve the stability of silicon-based solar cells. The different catalysts used are extensively discussed with experimental results indicating stable growth and highly efficient silicon nanowires for photovoltaic applications. To test the stability, we measured the open-circuit voltage for four hours and the change in voltage was ±0.05 V. The fabrication of all-crystalline silicon solar cells was demonstrated using the conventional mature industrial manufacturing process that is presently used for the amorphous silicon solar cells. To summarize, this research compares various post-transition metals as a catalyst for the growth of nanowires discussing their properties, and such silicon nanowires can be utilized in several other applications not only limited to photovoltaic research.

I. Introduction

Demand for renewable energy sources such as biomass, hydroelectricity, wind and solar energy is being increasingly debated. They are abundantly available, cheap, nontoxic, and do not pollute the environment. Among several renewable energy resources, solar energy has several advantages including its reliability, emission-free, eco-friendly, and many more. Silicon-based solar cells are still in high demand because of the abundance of raw material, their high stability, nontoxicity, and the compatibility of their fabrication with standard microelectronics industries [1]–[3]. To date, several attempts have been made to tackle the existing major challenges in silicon-based solar cells—to reduce the cost per watt by reducing the amount of material, increasing the efficiency and minimizing the fabrication costs.