Solar Cells Based on Two-Dimensional WTe2/PtXY (X, Y = S, Se) Heterostructures with High Photoelectric Conversion Efficiency and Low Power Consumption

High-effective two-dimensional (2D) solar cells have stimulated people's interest and enthusiasm. In this paper, the photoelectric properties of 2D heterostructures consist of WTe2 and PtXY (X, Y = S, Se) are studied by using first-principles calculations and non-equilibrium Green's function. The calculated results show that the constructed heterostructures are type II band alignment semiconductors with good stability, high electron mobility, and excellent light absorption. Meanwhile, the photoelectric conversion efficiency (PCE) of WTe2/PtSe2 and WTe2/SePtS heterostructures can reach as high as 21.43 and 19.86%, respectively. In addition, we find that the 2D NbS2 and TaS2 are Ohmic contact electrodes for the WTe2/PtSe2 heterostructures. Based on these Ohmic contact structures, we further designed the corresponding solar cells and evaluated their photoelectric performance. TaS2 and (WTe2/PtS2)(zigzag) solar cells were found to be appealing, owing to its highest PCE and the lowest heat consumption of the device. These results qualify 2D WTe2/PtXY (X, Y = S, Se) heterostructures as promising candidates for high-performance solar cells.