Photovoltaic Heterojunctions of Fullerenes with MoS₂ and WS₂ Monolayers

Abstract

First-principles calculations are performed to explore the geometry, bonding, and electronic structures of six ultrathin photovoltaic heterostructures consisting of pristine and B- or N-doped fullerenes and MoS2 or WS2 monolayers. The fullerenes prefer to be attached with a hexagon parallel to the monolayer, where B and N favor proximity to the monolayer. The main electronic properties of the subsystems stay intact, suggesting weak interfacial interaction. Both the C60/MoS2 and C60/WS2 systems show type-II band alignments. However, the built-in potential in the former case is too small to effectively drive electron-hole separation across the interface, whereas the latter system is predicted to show good photovoltaic performance. Unfortunately, B and N doping destroys the type-II band alignment on MoS2 and preserves it only in one spin channel on WS2, which is unsuitable for excitonic solar cells. Our results suggest that the C60/WS2 system is highly promising for excitonic solar cells.

MoS2/Si Heterojunction with Vertically Standing Layered Structure for Ultrafast, High‐Detectivity, Self‐Driven Visible–Near Infrared Photodetectors

“…Note that the power conversion effi ciency for the selfpowered MoS 2 /Si heterojunction is ≈0.26% under a light intensity of 30 mW cm −2 , which is somewhat smaller than the previous reports for MoS 2 sheet-based solar cells. [ 14,15,24,25 ] The carrier recombination induced by the defects at the junction interface and in the bulk fi lm is suggested to be responsible for the lower effi ciency. Various improvements can be envisioned, such as improvement of the crystal quality of MoS 2 fi lm by optimizing growth conditions and implementation of surface/interface passivation to reduce carrier recombination.…”

“…[ 14 ] The thinnest photovoltaic devices were developed from the MoS 2 /graphene and WS 2 /MoS 2 stacked monolayers, which showed power conversion effi ciencies of 1%, corresponding to one to three orders of magnitude higher power densities than the existing solar cells. [ 15,25 ] As a key component for the nano-optoelectronic system, photodetectors based on semiconductor nanostructures have attracted much attention. [ 26,27 ] For practical applications, e.g., imaging and optical communication, fast response speed and high sensitivity of the photodetectors are much desirable.…”

Optoelectronic Devices Based on Atomically Thin Transition Metal Dichalcogenides

“…Moreover, TMDs are interesting from a technological point of view, as they are chemically stable, environmentally sustainable and can potentially be produced at low cost. Calculations of graphene/MoS 2 [92] and WS 2 /MoS 2 [93] monolayer heterojunction solar cells predict a maximum power conversion efficiency of~1%, limited by the, in absolute numbers, low optical absorption of the atomically thin materials. Absorption enhancement is therefore necessary and can be achieved by stacking of 2D materials, using few-layer sheets or exploiting plasmonic effects [94].…”

MoS2@ZnO nano-heterojunctions with enhanced photocatalysis and field emission properties

“…MoS 2 @CdS heterojunctions with high photoelectrochemical activities for H 2 evolution and MoS 2 @WS 2 heterostructures with good electronic and photovoltaic performances have also been reported in recent years. 15,22 However, much less research has been carried out on the MoS 2 @ZnO nanoheterjunctions.…”