Bandgap Engineering of CIGS: Active Control of Composition Gradient
Open Access
Abstract
The tunable bandgap of CIGSe has established bandgap engineering as a pivotal research direction for advancing the efficiency frontiers of solar cells. In particular, the proposal of the V-shaped bandgap gradient has motivated extensive efforts to achieve precise control over elemental composition and spatial distribution within the absorber layer. Against this backdrop, this review systematically classifies active control strategies—such as surface sulfurization, Ga grading, and Ag alloying—according to their doping mechanisms and the resulting bandgap profiles. It further evaluates emerging profiles, including the “hockey-stick” distribution, against the conventional V-shaped benchmark, and explores future pathways for bandgap engineering in next-generation, high-efficiency photovoltaic devices. Further improvements in photovoltaic efficiency can effectively boost power generation and lower solar power costs, providing a practical solution to future energy and environmental challenges.Keywords
Funding Information
- National Key Research and Development Program of China (2024YFB4205300)
This publication has 96 references indexed in Scilit:
- Achieving over 860 mV Open‐Circuit Voltage in Low‐Ag Wide‐Bandgap Cu(In,Ga)Se2 Solar Cells Through Ion Diffusion and Band Structure OptimizationAdvanced Functional Materials, 2025
- Efficiency Boost of (Ag0.5,Cu0.5)(In1‐x,Gax)Se2 Thin Film Solar Cells by Using a Sequential Process: Effects of Ag‐Front Grading and Surface Phase EngineeringAdvanced Energy Materials, 2023
- Interconnection between Trait, Structure, and Composition of Grain Boundaries in Cu(In,Ga)Se2 Thin‐Film Solar CellsAdvanced Functional Materials, 2020
- Surface Cleaning and Passivation Using (NH4)2S Treatment for Cu(In,Ga)Se2 Solar Cells: A Safe Alternative to KCNAdvanced Energy Materials, 2014
- Gallium gradients in Cu(In,Ga)Se2thin-film solar cellsProgress in Photovoltaics: Research and Applications, 2014
- Formation of CuInSe2 and CuGaSe2 Thin‐Films Deposited by Three‐Stage Thermal Co‐Evaporation: A Real‐Time X‐Ray Diffraction and Fluorescence StudyAdvanced Energy Materials, 2013
- Wide bandgap Cu(In,Ga)Se2solar cells with improved energy conversion efficiencyProgress in Photovoltaics: Research and Applications, 2012
- Ternary and multinary Cu‐chalcogenide photovoltaic materials from CuInSe2 to Cu2ZnSnS4 and other compoundsProgress in Photovoltaics: Research and Applications, 2012
- Investigation of Cu(In,Ga)Se2thin‐film formation during the multi‐stage co‐evaporation processProgress in Photovoltaics: Research and Applications, 2011
- Studies on sulfur diffusion into Cu(In,Ga)Se2 thin filmsProgress in Photovoltaics: Research and Applications, 2000