Theoretical Modelling of InPBi/InGaAs Quantum Dot Superlattices for Intermediate Band-Based Solar Cell Applications

Abstract

Dilute bismide alloys such as InPBi exhibit strong bandgap reduction and enhanced spin-orbit splitting, making them promising candidates for intermediate band (IB) optoelectronic devices, including intermediate band solar cells (IBSCs). This report presents comprehensive Kronig-Penney model simulations of InPBi/AlGaAs quantum dot superlattices (QDSLs) for Intermediate band solar cell (IBSC) applications. The intermediate band (IB) characteristics including IB width, valence band to IB gaps and IB to conduction band gaps are systematically investigated as functions of well width and barrier thickness. Results are compared with existing theoretical models and experimental studies on similar material systems, including InAs/GaAs quantum dots and dilute bismide alloys. The simulations reveal optimal structural parameters achieving nearly balanced gaps within an IB width of 0.154 eV. These findings agree well with experimental report on InAs/GaAs quantum dot IBSCs and theoretical predictions for dilute nitride and bismide systems validating the applicability of the Kronig-Penney model for QDSL design.