Gour Kuldeep Singh, Pawar Pravin S, Lee Minwoo, Karade Vijay C, Yun Jae Sung, Heo Jaeyeong, Park Jongsung, Yun Jae Ho, Kim Jin Hyeok
Surface Engineering Group, Advanced Materials & Processes Division,CSIR-National Metallurgical Laboratory, Jamshedpur 831007, India.
Department of Energy Engineering, Korea Institute of Energy Technology (KENTECH), Naju, Jeonnam 58217, Republic of Korea.
ACS Appl Mater Interfaces. 2024 Jun 12;16(23):30010-30019. doi: 10.1021/acsami.4c02432. Epub 2024 May 30.
The present study demonstrates that precursor passivation is an effective approach for improving the crystallization process and controlling the detrimental defect density in high-efficiency CuZnSn(S,Se) (CZTSSe) thin films. It is achieved by applying the atomic layer deposition (ALD) of the tin oxide (ALD-SnO) capping layer onto the precursor (Cu-Zn-Sn) thin films. The ALD-SnO capping layer was observed to facilitate the homogeneous growth of crystalline grains and mitigate defects prior to sulfo-selenization in CZTSSe thin films. Particularly, the Cu and Sn defects and deep defects associated with Sn were effectively mitigated due to the reduction of Sn and the increase in Sn levels in the kesterite CZTSSe film after introducing ALD-SnO on the precursor films. Subsequently, devices integrating the ALD-SnO layer exhibited significantly reduced recombination and efficient charge transport at the heterojunction interface and within the bulk CZTSSe absorber bulk properties. Finally, the CZTSSe device showed improved power conversion efficiency (PCE) from 8.46% to 10.1%. The incorporation of ALD-SnO revealed reduced defect sites, grain boundaries, and surface roughness, improving the performance. This study offers a systematic examination of the correlation between the incorporation of the ALD-SnO layer and the improved PCE of CZTSSe thin film solar cells (TFSCs), in addition to innovative approaches for improving absorber quality and defect control to advance the performance of kesterite CZTSSe devices.
本研究表明，前驱体钝化是改善高效铜锌锡硫硒（CZTSSe）薄膜结晶过程和控制有害缺陷密度的有效方法。这是通过在（铜 - 锌 - 锡）前驱体薄膜上应用氧化锡原子层沉积（ALD - SnO）覆盖层来实现的。观察到ALD - SnO覆盖层有助于CZTSSe薄膜在硫硒化之前晶粒的均匀生长并减轻缺陷。特别是，在前驱体薄膜上引入ALD - SnO后，由于锡的减少以及硫锡铜矿CZTSSe薄膜中锡含量的增加，铜和锡缺陷以及与锡相关的深缺陷得到有效减轻。随后，集成了ALD - SnO层的器件在异质结界面处以及块状CZTSSe吸收体内部表现出显著降低的复合和高效的电荷传输特性。最终，CZTSSe器件的功率转换效率（PCE）从8.46%提高到了10.1%。ALD - SnO的引入减少了缺陷位点、晶界和表面粗糙度，从而提高了性能。本研究除了提供用于提高吸收体质量和缺陷控制以提升硫锡铜矿CZTSSe器件性能的创新方法外，还系统地研究了ALD - SnO层的引入与CZTSSe薄膜太阳能电池（TFSCs）PCE提高之间的相关性。
