Performance enhancement of solar cells based on high photoelectric conversion efficiency of h-BN and metal nanoparticles

Abstract

In this article, we propose a new type of CdTe thin-film solar cell based on a CdTe/CdS heterojunction. We used the finite difference time domain method to simulate the propagation of electromagnetic waves in the time domain under certain boundary conditions and the change in the absorption rate of cells when optimising the structure. The simulation shows that the light absorption rate of the cell is significantly enhanced after adding h-BN and metal particles to the proposed structure. Under the irradiation of standard light AM1.5 with the wavelength range of 300 nm to 1000 nm, presenting a 90% absorption bandwidth over 700 nm, and the average absorption rate is as high as 92.9%. The short-circuit current and open-circuit voltage are 30.98 mA/cm2 and 1.155 V, respectively, and the photoelectric conversion efficiency (PCE) increases to 30.76%, which is an increase of 27.58% compared to the original PCE. The result shows that, after metal nanoparticles are embedded in the absorption layer of the cell, the free electrons on the surface of the metal particles oscillate under the action of light. The electromagnetic field is confined to a small area on the surface of the particles and is enhanced, which is beneficial for the absorption of light by the cells. This study provides a basis for theoretical research and feasible solutions for the manufacture of thin-film solar cells with a high absorption rate and high efficiency.