Van der Waals Materials for Atomically-Thin Photovoltaics: Promise and Outlook

TL;DR

This paper reviews the potential of two-dimensional semiconductors for ultrathin photovoltaic devices, highlighting design strategies, efficiency estimates, and recent experimental progress towards lightweight, efficient solar cells.

Contribution

It provides a comprehensive perspective on 2D semiconductor photovoltaics, including device design, theoretical efficiency estimates, and recent experimental demonstrations, outlining future research directions.

Findings

2D semiconductors can be competitive with traditional photovoltaics.

Photonic and electronic design strategies enable efficient light absorption and carrier collection.

Recent experiments demonstrate promising ultrathin solar cell performance.

Abstract

Two-dimensional (2D) semiconductors provide a unique opportunity for optoelectronics due to their layered atomic structure, electronic and optical properties. To date, a majority of the application-oriented research in this field has been focused on field-effect electronics as well as photodetectors and light emitting diodes. Here we present a perspective on the use of 2D semiconductors for photovoltaic applications. We discuss photonic device designs that enable light trapping in nanometer-thickness absorber layers, and we also outline schemes for efficient carrier transport and collection. We further provide theoretical estimates of efficiency indicating that 2D semiconductors can indeed be competitive with and complementary to conventional photovoltaics, based on favorable energy bandgap, absorption, external radiative efficiency, along with recent experimental demonstrations. Photonic and electronic design of 2D semiconductor photovoltaics represents a new direction for realizing ultrathin, efficient solar cells with applications ranging from conventional power generation to portable and ultralight solar power.