Photovoltaic functionality assessment of InPBi-based solar cells using a combination of density functional theory and finite element method analysis

Abstract

This work reports the theoretical investigation of the effect of incorporation of dilute Bismuth (Bi) on the optical and electronic properties of zinc blende (ZB) phase Indium Phosphide (InP) using the full-potential linearized augmented plane wave (FP-LAPW) basis set, Perdew-Burke-Ernzerhof (PBE) exchange–correlation (XC) function, and the Tran Blaha modified Becke-Johnson (TB-mBJ) potential in the density functional theory (DFT) computational framework. The obtained results show that the introduction of large-sized Bi impurities into InP increases the lattice constant and reduces the bandgap by 52 meV/Bi%. We have also presented the design of an InP/InP_1−xBi_x/InP planar solar cell (SC) utilizing the computed optical and electronic properties of the investigated InP_1-xBi_x alloy to produce SC with an average absorptance of 65.14% and 62.91% with Bi incorporation of 3.125% and 6.25%, respectively, and an optical current density (J_opt) of 29.45 mA/cm² for Bi concentration of 6.25%. We also thoroughly analyzed two additional parameters, namely the electric field distribution and photogeneration rate. By adding 6.25% Bi into InP, we obtained a band gap of 1 eV, which is perfect for SC design. With this SC, we got the highest short-circuit current density (J_sc) of 23.23 mA/cm² and power conversion efficiency (PCE) of 14.53 %.