Enhanced Photovoltaic Performance of Cu(In,Ga)Se2 Solar Cells Via Quantum Well Engineering: A Computational Optimization Study Achieving 28.53% Efficiency

Abstract

This study presents a comprehensive computational investigation of Cu(In,Ga)Se₂ (CIGS) quantum well solar cells (QWSC) using SCAPS-1D simulation framework to enhance photovoltaic performance through advanced band engineering. We demonstrate that the strategic implementation of quantum well structures within CIGS absorber layers significantly improves charge carrier dynamics and light absorption efficiency. Our optimized CIGS-QWSC configuration achieves a remarkable power conversion efficiency of 28.53%, representing a 31.5% improvement over conventional CIGS cells (23.93%). The quantum well design incorporates alternating CIGS barrier (Eg = 1.41 eV) and well (Eg = 1.18 eV) layers with optimized thickness of 10 nm each, creating favorable energy band alignment for enhanced carrier collection. Key performance metrics include: open-circuit voltage (Voc) of 1.101 V, short-circuit current density (Jsc) of 33.117 mA/cm², and fill factor (FF) of 78.27%. Comprehensive parametric optimization reveals that quantum well depth of 0.23 eV and carrier concentration of 2×10¹⁶ cm^-3 provide optimal photovoltaic performance. The quantum confinement effects enhance absorption coefficient by 2.3× in the near-infrared region while maintaining excellent charge transport properties. This computational methodology provides crucial insights for next-generation thin-film photovoltaic technology development.