Graphene/Silicon Heterojunctions: Preparation, Performance Optimization, and Applications

Abstract

The unique photoelectric properties of graphene/ Silicon (Gr/Si) heterojunction make this structure a very interesting candidate to promote optoelectronic technology. This paper reviews the latest progress in the synthesis, optimization and application of Gr/Si heterojunction in three main fields: photovoltaic conversion, optical sensing and electrochemical energy storage. For synthesis, chemical vapor deposition (CVD) is still the best method to obtain uniform and high-quality graphene on large surfaces, and its combination with wet or dry transfer protocols allows the construction of reliable heterojunctions. The performance of the equipment can be improved by many means, such as chemical hybridization to adjust the carrier density, modify the interface to reduce recombination, photon management structure to increase absorption, and accurate control of graphene thickness. In order to capture solar energy, the efficiency of Schottky Gr/Si battery has increased from the initial 1.5% to more than 15% now. The photoelectric sensors constructed on these isomers have broad spectral coverage, high responsiveness and fast time response. In addition, Gr/Si composites show strong electrochemical performance when configured as electrodes of supercapacitors or lithium ion batteries.