Novel Design of polycrystalline CdTe/Si Tandem Solar Cells Using SiO2/TiO2 Distributed Bragg Reflector

In this paper, for the first time, a polycrystalline cadmium telluride/silicon (CdTe/Si) solar cell based on SiO2/TiO2 distributed Bragg reflector (DBR) is proposed and investigated using calibrated simulations with experimental data of fabricated. At first, by inserting the SiO2/TiO2 DBR, the conversion efficiency is increased by about 25% compared with the conventional CdTe/Si solar cell with similar dimensions. In addition, the carrier lifetime of absorber layer can provide improved conversion efficiency of device about 15% compared with the CdTe/Si conventional solar cell. The obtained open circuit voltage, short circuit current density, fill factor and conversion efficiency of proposed solar cell structure were about 1.2 V, 39.5 mA/cm2, 0.95 and 28.5% under global AM 1.5 conditions, respectively. The results strongly confirm that the polycrystalline CdTe/Si solar cell based on SiO2/TiO2 DBR seems to be the most optimal choice for converting the solar energy in high efficiency photovoltaics systems.