https://scholars.lib.ntu.edu.tw/handle/123456789/633928
標題: | Modulation and Direct Mapping of the Interfacial Band Alignment of an Eco-Friendly Zinc-Tin-Oxide Buffer Layer in SnS Solar Cells | 作者: | Ho, Thi Thong Yang, Zi Liang Fu, Fang Yu Jokar, Efat Hsu, Hung Chang Liu, Pei Chi Quadir, Shaham Chen, Cheng Ying YA-PING CHIU CHIH-I WU Chen, Kuei Hsien LI-CHYONG CHEN |
關鍵字: | Cd-free buffer layer | eco-friendly solar cells | interface engineering | SnS-based photovoltaics | zinc-tin-oxide buffer layer | 公開日期: | 28-十一月-2022 | 卷: | 5 | 期: | 11 | 來源出版物: | ACS Applied Energy Materials | 摘要: | In thin-film solar cells (TFSCs), the buffer layer plays a vital role in enhancing the power conversion efficiency (PCE) by improving the charge carrier dynamics. In the present study, a series of eco-friendly Zn1-xSnxOy (ZTO, 0 ≤ x ≤ 1) films grown by atomic layer deposition are used as buffer layers in the SnS-based TFSCs. We systematically investigate the effect of the Zn-to-Sn ratio on the band alignment at the SnS/ZTO heterojunction. The results revealed that by controlling the Zn-to-Sn ratio in the ZTO films, the energy band alignment changed from a "cliff-type"(9%Sn-ZTO41) to a "spike-type"(18%Sn-ZTO11). The spike-type band configuration with appropriate conduction band offset (CBO<0.4 eV) at the SnS/ZTO11 junction is visualized by cross-sectional scanning tunneling microscopy. This favorable CBO at the heterojunction reduces the interfacial recombination and enhances the charge collection probability in the ZTO11 device, ultimately significantly improving the open-circuit voltage (Voc) from 0.24 V to 0.34 V. The charge recombination mechanisms in the ZTO-based TFSCs is elaborated and compared with the CdS-based one, and the result confirms the charge recombination suppression at the SnS/ZTO11 interface. Moreover, the photocurrent in all ZTO-based TFSCs is significantly higher than CdS-based ones due to the broader band gap of ZTO compared to CdS. Improvements in Voc and Jsc significantly increase the PCE from 1.7% (CdS buffer layer) to 3% (ZTO11 with 18% Sn). This study highlights the potential of ZTO as an effective and environmentally friendly buffer layer in anisotropic photovoltaic materials. |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/633928 | ISSN: | 2574-0962 | DOI: | 10.1021/acsaem.2c03129 |
顯示於: | 物理學系 |
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