Tandem Photovoltaics from 2D Transition Metal Dichalcogenides on Silicon

TL;DR

This paper proposes a tandem photovoltaic system combining 2D TMDC materials with silicon to significantly enhance efficiency, demonstrating a nearly 29% power conversion efficiency through optimized design and simulations.

Contribution

It introduces a novel TMDC superlattice top cell integrated with silicon, achieving higher efficiency in tandem solar cells through geometric optimization and simulation.

Findings

Achieved a PCE of 28.96% with the optimized design.

Demonstrated a 5.68% efficiency increase over single-junction silicon cells.

Optimized superlattice geometry enhances photon absorption and structural stability.

Abstract

The demand for high-efficiency photovoltaic systems necessitates innovations that transcend the efficiency limitations of single-junction solar cells. This study investigates a tandem photovoltaic architecture comprising a top-cell with a transition metal dichalcogenide (TMDC) superlattice absorber and a bottom-cell of crystalline silicon (c-Si), focusing on optimizing the light absorption and electrical performance of the combined structure. Through the transfer matrix method and electrical simulations, we optimized the geometry of the superlattice, determining that a siz-layer MoSe2 configuration with a 40 nm SiO2 antireflective layer maximizes photon absorption while mitigating additional weight and preserving the cell's structural integrity. The results show that the optimized TMDC superlattice significantly improves the PCE of the tandem design to 28.96%, and increase of 5.68% over the original single-junction c-Si solar cell's efficiency. This advancement illustrates the potential of TMDC material in next-generation solar cells and presents a promising avenue for the development of highly efficient, tandem photovoltaic systems via van der Waals integration of the top cell on c-Si