Advancements in photovoltaic efficiency: The role of fluorine-doped CZTS in homojunction solar cells
Milad Yousefizad, Zohreh Golshan Bafghi, Alireza Shahriyari, Andia Javanmardi, Naser Hakimi Raad, Ashraf Ahmadi Shadmehri, Siavosh Samoodi, Negin Manavizadeh, A. Moafi
Abstract
Copper Zinc Tin Sulfide (CZTS) solar cells have absorbed significant appeal as an efficient approach for sustainable photovoltaic technology. This research introduces a groundbreaking approach to thin-film solar cells using a novel Fluorine-doped CZTS composition with a new device configuration. The DFT calculations indicate that F atoms prefer Cu sites and maintain a direct band gap in CZTS, promoting n-type conductivity. Optical studies demonstrate that F-doping enhances conductivity, refractive index, and light absorption through the visible spectrum. Furthermore, the performance of CZTS-based cells in both heterojunction and homojunction configurations is under investigation. The homojunction configuration with Al:ZnO intermediate layer enhances V OC and J SC compared to conventional heterojunction structures. The J SC and V OC of homojunction solar cells with AZO layer are 24.74 mAcm −2 and 0.94 V, respectively. The efficiency of the solar cell is optimized considering the thickness of the p-CZTS layer, which saturates at 21.8 % beyond 5 μm thickness. At the beginning of near-infrared wavelengths, the homojunction structure effectively absorbs light. Combining F-doped CZTS and homojunction configuration with a ZnO and AZO intermediate layer demonstrates superior performance due to reduced carrier recombination and enhanced photogeneration. The novel homojunction design advances CZTS-based technology, achieving impressive effectiveness using environmentally friendly materials.