Photocurrent generation in graphene/h-BN heterostructures under solar illumination

Abstract

Graphene/h-BN tunneling heterostructures have considerable potential for developing future optoelectronic devices including solar cells because of their unique properties. To date, theoretical studies have been constrained to a single graphene insulator graphene-tunneling junction. We demonstrate how photocurrents can be generated in multilayer graphene/h-BN heterostructures. We compute the steady-state carrier occupation in graphene by solving the Boltzmann transport equation under a standard 1 sun illumination with electron–phonon and electron–electron scattering. An energy balance equation is used to normalize the carrier distribution function. The effect of the heterostructure and rotational alignment on the photocurrent is discussed. We obtained heterostructure designs to produce photocurrents above 17 mA/cm2. Our approach based on the formation of a graphene/h-BN multilayer structure is a promising candidate for high-performance photovoltaic devices.