Strategies for inhibiting the growth defects of CZTSe thin film

• Published in: Journal of alloys and compounds Vol. 1000
• Main Authors: Li, Dongying, Zeng, Chunhong, Xin, Wanjie, Zi, Guangting, Hong, Ruijiang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.09.2024
• Subjects: CZTSe solar cells; Growth defects; Metal alloying; Pre-annealing process; Growth defects; CZTSe solar cells; Metal alloying; Pre-annealing process
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2024.175105

Growth defects are imperfections that appear during crystal formation.It is found that there are particle migration and crystalline phase decomposition behaviors during the crystal growth of CZTSe. By studying different annealing process paths, a selenium-free pre-annealing process strategy was proposed. It has been observed that under the condition of pre-annealing at 350℃ without selenium, the migration behavior of each element can be effectively controlled as the temperature increases. This process facilitates the formation of alloy phases and inhibits the generation of heterophase during the crystallization process. Simultaneously, the low-temperature pre-annealing treatment helps to reduce the decomposition of CZTSe during the annealing process, thereby minimizing defects. The large grains formed can also mitigate the carrier recombination issue caused by grain boundaries. In addition, the impact of pre-annealing temperature on crystallization quality was investigated. It was observed that there is a temperature threshold for enhancing crystallization, which should not exceed 400℃. As a result, the efficiency of the cells prepared using this strategy increased by nearly 50 %. •The strategy of a selenium-free pre-annealing process was proposed to inhibit defects in CZTSe crystallization.•The decomposition phenomenon in CZTSe crystallization was studied, and the particle migration law was summarized. This promoted the alloying of metals and facilitated the uniform growth of crystals.•The effect of temperature on the quality of pre-annealed crystallization is clarified. Reveal suitable temperature for crystallization and optimize the annealing process.