First principles guided device fabrication of arsenic doped CdTe photovoltaics

The doping effect of arsenic (As) concentration in the CdTe absorber has been studied by using the first principles method. Atomistic modeling based on density functional theory (DFT-1/2) and green’s function (GF) was utilized to simulate a first order approximated model of As doped CdTe surface. The band alignment results calculated using DFT-1/2 revealed that higher concentration of As doping at CdTe surface is required to obtain favorable band bending for hole charge carrier transport. Based on the results obtained from DFT models, CdTe solar cells were fabricated with two different As dopant concentrations. The experimental finding corroborates the theoretical result and provides a future pathway of using DFT simulations as a precursor in guiding the CdTe device fabrication experiments.