Functionalized Graphene and Hexagonal Boron Nitride (hBN) Two-Dimensional Heterosystems for Solar Cell Applications

Abstract

ABSTRACT:We present preliminary results of theoretical investigation of mono-and multi-layers of graphene (G), hexagonal boron nitride (hBN) and/or their combinations, functionalized with hydrogen, which are prospective for photovoltaic (PV) applications. Controlled hydrogenation of the above layered systems allows to simultaneously tune 2D electron gap of the materials, create strong covalent interlayer bonding or bond the multilayers to a substrate. The functionalized nanomaterials under investigation demonstrate not only chemical stability and natural hardness, but they are also compatible with standard growth technologies used in photovoltaics. Such multilayers can be used as transparent solar cell windows, an interfacial layer, e.g., in a form of a tunnel junction, an electrode, 2D semiconducting material and other. In particular, graphene/hBN heterosystems considered, allow tailoring of structural, electronic and bonding properties by controlled dose of hydrogen. Their promising PV applications as well as already existing experimental implementations will be discussed in the end.

Density functional theory studies on graphene/h-boron nitride hybrid nanosheets for supercapacitor electrode applications

“…34 As a result, the h-BN and graphene nanosheets appear to have many common properties, such as non-solubility in water, atomic structure, transparency, high mechanical strength, and thermal conductivity coupled with weak van der Waals interaction between layers and with substrate materials. 35 Further, the h-BN nanosheet has a band gap of 4.6 eV, and graphene is a semi-metal with zero band gap. 36 The band gap of pristine graphene and boron nitride can be altered by doping either carbon into h-BN or vice versa, 37,38 as they exhibit an isoelectronic nature.…”

“…44 They also studied the electronic and structural properties of graphene/h-BN hybrid nanosheets with and without vacancies and showed that the vacancies weaken the atomic bonds in the hybrid nanosheet with reduced band gaps. 45 So far, theoretically, researchers have examined the graphene/h-BN hybrid nanosheet for potential applications such as electronics, 45 optoelectronic devices, 33 solar cells, 35 photo redox catalysis, 46 spintronic devices, 47 nanodevices for surface acoustic wave sensors, and waveguides. 48 Experimentally, the h-BN/rGO hybrid superlattice and the rGO/BN/Ni(OH)2 hybrid nanocomposite were used as an electrode material and were observed to have a higher energy density.…”