MXene-Contacted Silicon Solar Cells with 11.5% Efficiency

Abstract

MXene, a new class of 2D materials, has gained significant attention owing to its attractive electrical conductivity, tunable work function, and metallic nature for wide range of applications. Herein, delaminated few layered Ti3C2Tx MXene contacted Si solar cells with a maximum power conversion efficiency (PCE) of ≈11.5% under AM1.5G illumination are demonstrated. The formation of an Ohmic junction of the metallic MXene to n+-Si surface efficiently extracts the photogenerated electrons from n+np+-Si, decreases the contact resistance, and suppresses the charge carrier recombination, giving rise to excellent open-circuit voltage and short-circuit current density. The rapid thermal annealing process further improves the electrical contact between Ti3C2Tx MXene and n+-Si surface by reducing sheet resistance, increasing electrical conductivity, and decreasing cell series resistance, thus leading to a remarkable improvement in fill factor and overall PCE. The work demonstrated here can be extended to other MXene compositions as potential electrodes for developing highly performing solar cells.