Optical design of ultra-thin GaAs solar cells based on trapezoidal pyramid structure

Abstract

This study analyzed the solar absorption characteristics of Trapezoidal Pyramid ultra-thin GaAs solar cells (GTCs) using the finite difference time domain (FDTD) method. The study explored the influence of geometric parameters of trapezoidal pyramid structures (TPs) in GTCs, including different heights and up/down ratios, on the photoelectric characteristics of GTCs. Ultra-thin GaAs solar cells containing TPs exhibited an optical absorption rate exceeding 90 % under the AM1.5 solar spectrum (300–1100 nm), with an average of 95.55 %. The short-circuit current density (Jsc), open-circuit voltage (Voc), and maximum power (Pmax) were calculated using DEVICE software, and the geometric structure of GTCs was optimized based on the maximum value of Jsc. The electrical simulation results show that the maximum Jsc was 33.83mA/cm2. The Jsc of GTCs was 30.97 % higher than that of Ultra-thin GaAs solar cells without TPs (planar GACs), resulting in a PCE of 24.34 %. These findings demonstrate that the TPs array has a strong optical capture effect and highlight the significant potential of GTCs in solar absorption. This work provides valuable insights for the structural design of GaAs solar cells and suggests that further exploration will lead to even greater improvements in the PCE of GaAs solar cells.