TY - JOUR
T1 - Manifold benefits of vacuum annealed molybdenum back contact for enhanced CZTSSe thin film properties and device
AU - Putthisigamany, Yoganash
AU - Hossain, Mohammad Istiaque
AU - Zekri, Atef
AU - Aïssa, Brahim
AU - Rahman, Kazi Sajedur
AU - Izhar Sapeli, Mohd Megat
AU - Su'ait, Mohd Sukor
AU - Ludin, Norasikin Ahmad
AU - Ibrahim, Mohd Adib
AU - Chelvanathan, Puvaneswaran
N1 - Publisher Copyright:
© 2025 Elsevier B.V.
PY - 2025/10/15
Y1 - 2025/10/15
N2 - Cu2ZnSn(SxSe1−x)4 (CZTSSe) thin-film solar cell (TFCS) are emerging as favourable materials for sustainable energy production, offering advantages such as low cost, abundance, and non-toxicity. Despite the significant progress in CZTSSe solar cells, optimizing their performance remains challenging due to factors like back contact material and interfacial layer formation. Molybdenum (Mo) is commonly used as a back contact material due to its robustness and compatibility with the absorber layer. However, the work function of Mo is highly sensitive to its deposition conditions, which can influence the device's open-circuit voltage (Voc) and resistance. Our study investigates the impact of Mo work function optimization through post-deposition treatments, such as vacuum annealing, to enhance the electrical and morphological properties of Mo films. Additionally, the growth of Mo(S,Se)2 layers at the Mo/CZTSSe interface and its influence on the device's performance is studied. We thereby demonstrate that post-deposition annealing of Mo can significantly improve the work function, reduce interfacial layer thickness, and enhance the overall photovoltaic performance of CZTSSe solar cells. Our findings reveal that the optimized Mo back contact results in an improved power conversion efficiency, with Mo_VA-treated films achieving 7.7 % efficiency compared to 0.71 % efficiency for as-sputtered Mo films, highlighting the critical role of back contact optimization in CZTSSe-based photovoltaics.
AB - Cu2ZnSn(SxSe1−x)4 (CZTSSe) thin-film solar cell (TFCS) are emerging as favourable materials for sustainable energy production, offering advantages such as low cost, abundance, and non-toxicity. Despite the significant progress in CZTSSe solar cells, optimizing their performance remains challenging due to factors like back contact material and interfacial layer formation. Molybdenum (Mo) is commonly used as a back contact material due to its robustness and compatibility with the absorber layer. However, the work function of Mo is highly sensitive to its deposition conditions, which can influence the device's open-circuit voltage (Voc) and resistance. Our study investigates the impact of Mo work function optimization through post-deposition treatments, such as vacuum annealing, to enhance the electrical and morphological properties of Mo films. Additionally, the growth of Mo(S,Se)2 layers at the Mo/CZTSSe interface and its influence on the device's performance is studied. We thereby demonstrate that post-deposition annealing of Mo can significantly improve the work function, reduce interfacial layer thickness, and enhance the overall photovoltaic performance of CZTSSe solar cells. Our findings reveal that the optimized Mo back contact results in an improved power conversion efficiency, with Mo_VA-treated films achieving 7.7 % efficiency compared to 0.71 % efficiency for as-sputtered Mo films, highlighting the critical role of back contact optimization in CZTSSe-based photovoltaics.
KW - CZTSSe
KW - Interfaces
KW - Mo work function
KW - Na diffusion
KW - Solar cells
UR - https://www.scopus.com/pages/publications/105007695342
U2 - 10.1016/j.solmat.2025.113782
DO - 10.1016/j.solmat.2025.113782
M3 - Article
AN - SCOPUS:105007695342
SN - 0927-0248
VL - 292
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
M1 - 113782
ER -