Broadband perfect light trapping in the thinnest monolayer graphene-MoS$_{2}$ photovoltaic cell

TL;DR

This paper demonstrates a monolayer graphene-MoS2 photovoltaic cell with up to 98% light absorption using a microcavity, surpassing traditional nanophotonic limits and enabling efficient, ultra-thin solar energy harvesting.

Contribution

It introduces a novel microcavity design that achieves near-perfect light trapping in a monolayer photovoltaic cell, exceeding existing absorption limits.

Findings

Achieves 98% light absorption in a 3x thinner cell.

Maintains at least 90% absorption despite errors.

Provides design methods for light-trapping and spectrum-splitting.

Abstract

The light absorption of a monolayer graphene-molybdenum disulfide photovoltaic (GM-PV) cell in a wedge-shaped microcavity with a spectrum-splitting structure is investigated theoretically. The GM-PV cell, which is three times thinner than the traditional photovoltaic cell, exhibits up to 98\% light absorptivity in a wide wavelength range. This rate exceeds the fundamental limit of nanophotonic light trapping in solar cells. The effects of defect layer thickness, GM-PV cell position in the microcavity, incident angle, and lens aberration on the light absorption rate of the GM-PV cell is explored. Regardless of errors, the GM-PV cell can still achieve at least 90\% light absorptivity with the current technology. Our proposal provides different methods to design light-trapping structures and apply spectrum-splitting systems.