Numerical analysis of Ga gradient effects in ACIGS absorbers for high-efficiency tandem solar cells

被引：0

作者：

Nour El I. Boukortt ^{[1
]}

Antonio Garcia Loureiro ^{[2
]}

Ohood A. Almutairi ^{[1
]}

机构：

[1] University of Santiago de Compostela,Centro Singular de Investigación en Tecnoloxías Intelixentes

[2] Ghent University,Department of Electronics and Information Systems

[3] University College London,Department of Electronic and Electrical Engineering

[4] College of Engineering & Energy,Energy Systems Program

[5] Abdullah Al Salem University,undefined

来源：

Optical and Quantum Electronics | / 57卷 / 3期

关键词：

ACIGS; Tandem; Solar cell; Bandgap grading; Efficiency;

D O I：

10.1007/s11082-025-08092-5

中图分类号：

学科分类号：

摘要：

Ag-alloyed Cu(In,Ga)Se₂ (ACIGS) is a promising material for the bottom subcell in tandem solar cell structures, offering a tunable bandgap that spans the optimal range for maximum efficiency; however, the bandgap widening of ACIGS thin films poses a significant challenge in enhancing their photocurrent. This paper investigates the impact of different grading profiles, specifically focusing on the 'hockey stick'/V-like Ga gradient–induced (GGI) profiles, on the performance of thin-film ACIGS cells. To enhance the physical understanding of these grading profiles we have used Silvaco TCAD tools to analyze how these profiles' depths, notch position, and slope affect the power conversion efficiency (PCE). The optimized ACIGS cell achieves a PCE of 25.80%, compared to 23.60% for the reference device. For the tandem configuration, we pair the optimized ACIGS bottom cell (double grading profile) with a perovskite top cell (band gap ~ 1.66 eV), achieving an overall efficiency of 30.26% under AM1.5G illumination. The obtained results highlight the critical role of Ga gradient profiles in enhancing the bottom cell's performance and stability. Additionally, we compare our results with existing studies to evaluate the broader impact of Ga compositional optimization on ACIGS-based solar cells. This work provides valuable insights into advanced grading strategies and helps us understand the physical behaviour of these high-performance tandem solar cells.

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