Improvement of CZTS solar cell by hydrogen doping

• Main Author: Chua, Maynard Wen De
• Other Authors: Lydia Helena Wong
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Materials
• Online Access: http://hdl.handle.net/10356/76748
• Institution: Nanyang Technological University

In recent years, developments in achieving higher device performance are conducted as its highest efficiency is 12.6% and have been stagnant so far. To further improve its performance, hydrogen offer a unique pathway as it has been successful in a-Si and Cu2InGaSe4 solar cell. Therefore, in this study, we investigate on the different parameters of hydrogen post treatment was conducted to study their effects on Cu2ZnSnS4 (CZTS). CZTS films were successfully fabricated on Molybdenum-coated glass by spin coating technique and subsequent annealing in sulphur atmosphere. This was followed by hydrogenation process with variation in process parameters such as temperature, time and flow rate, to achieve highest improvement in solar cell performance. Current-voltage and external quantum efficiency measurement were conducted on these samples. The device shows better uniformity across the surface for CZTS absorber layer hydrogenated at 100°C and 200°C, 10 minutes and without H2 gas flow rate. The peak shift is observed at (112) plane as hydrogenation temperature increases. Furthermore, different hydrogenation parameter also shows effect on the ratio between Molybdenum and CZTS peak. Energy-dispersive. There is a change in the chemical atomic ratio with different hydrogenation temperature. A simple experiment was also conducted to assess the effect of hydrogen gas by using 100% Argon gas throughout the process in the hydrogenation process. The results showed that hydrogen gas did played a part in improving the efficiency of CZTS. Based on these results, it is shown that hydrogenation provide a unique pathway to improve solar cell performance in CZTS. The highest average efficiency is achieved at 4.44% for CZTS absorber layer hydrogenated at 200°C, 30 minutes and H2 gas flow rate of 40 sccm. The average efficiency of the non-hydrogenated sample is 3.53%.