Simulation of graphene-GaAs Schottky junction solar cell with graphene gate by finite difference method

Simulation of graphene-GaAs Schottky junction solar cell with graphene gate is performed by using finite difference method. Poisson and driftdiffusion equations are solved self-consistently to capture carrier dynamics in the solar cell. Our algorithm is verified by comparing with experimental results. The Schottky barrier between graphene and GaAs can be tuned by graphene gate, and hence the open circuit voltage is tunable due to the tunability of Schottky barrier. The carrier recombination in GaAs leads to loss of light generated carriers.

I. Introduction

Graphene owns excellent optical and electrical properties, such as ultra-high carrier mobility, high optical transmittance and low resistivity [1]. Benefiting from low density of states of graphene, the graphene-semiconductor Schottky barrier height and thickness can be tuned by either chemical doping or electrostatic gating, which is different from traditional Schottky junction [2]. Researchers pay extensive attention on the development of graphene-based optoelectronic and photovoltaic devices [1], [5].