Regulation of solar cell performance by cadmium sulfide/copper-based thin film heterojunction annealing under different atmospheres

Efficient copper based thin film solar cells usually use inorganic n-type semiconductor material CdS as the buffer layer. Therefore, interface quality and energy band matching between layer absorption are crucial to collection utilization of carriers. Heat treatment can promote mutual diffusion elements, migration ions in material, change defect state, appropriate temperature will Cu-Zn ordering degree layer, so improve efficiency cells. Based on optimization basic process, strategy annealing CdS/copper-based heterojunction sulfur atmosphere further improves film, is applied copper-based regulate p-n gap The results show that sulfur-containing inert effectively crystal inhibit non-radiative recombination loss caused by trapping at CZTS/CdS heterojunction, open-circuit voltage device significantly increase 718 mV. In addition, S/Ar matching, which not only electron transmission, but also reduces carrier recombination, thus improving <i>V</i><sub>oc</sub> FF device. Besides, oxygen element be replaced enhancing short-wave cell terms efficiency, CZTS sputtering method increases from 3.47% 5.68%, about twice non-annealing treatment. Its structure Glass/Mo/CZTS/CdS/i-ZnO/Al:ZnO/Ni/Al, providing a reliable process window for devices achieve high voltage. Meanwhile, this study strongly demonstrates importance selection heterojunction. addition interdiffusion, composition crystallinity controlled.