Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, P. R. China.
University of Science and Technology of China, Hefei 230026, P. R. China.
ACS Appl Mater Interfaces. 2023 May 24;15(20):24583-24594. doi: 10.1021/acsami.3c02843. Epub 2023 May 12.
Solution-processed material systems for effective photovoltaic conversion are the key to low-cost and efficient solar cells. While antimony trisulfide (SbS) is a promising photovoltaic absorber, solution-processed quality SbS-based heterojunction systems for solar cells, particularly with an open-circuit voltage () higher than 0.70 V, are challenging issues. Here, a cadmium sulfide (CdS) interfacial engineering method is developed for the SbS-based bulk-heterojunction (BHJ) solar cells with an efficiency of 6.14% and a up to 0.76 V that is the highest one among solution-processed SbS solar cells. The prepared SbS-based BHJ solar cells feature a SbS nanoparticle film interdigitated by a titania (TiO) nanorod array with a nanostructured CdS shell as an interfacial layer on each TiO nanorod core. Upon understanding the interfacial interactions and band alignments in the TiO-CdS-SbS system, the function of the CdS interfacial layer as a band-bended spatial spacer interacting strongly with both the TiO electron transporter and SbS absorber for increasing charge collecting efficiency is revealed; moreover, space-charging the band-bended CdS layer by illumination is found and a photogenerated interfacial dipole electric field model is proposed for understanding the high subjected to the presence of the CdS interfacial layer. This work provides a conceptual guide for designing efficient inorganic heterojunction solar cells.
用于有效光伏转换的溶液处理材料系统是低成本、高效率太阳能电池的关键。虽然三硫化二锑 (Sb2S3) 是一种很有前途的光伏吸收剂，但用于太阳能电池的溶液处理高质量 Sb2S3 基异质结系统，特别是开路电压（Voc）高于 0.70 V 的系统，仍然是具有挑战性的问题。在这里，开发了一种硫化镉 (CdS) 界面工程方法，用于 Sb2S3 基体异质结（BHJ）太阳能电池，其效率为 6.14%，Voc 高达 0.76 V，这是溶液处理 Sb2S3 太阳能电池中最高的。所制备的 Sb2S3 基 BHJ 太阳能电池具有 Sb2S3 纳米颗粒薄膜，其由 TiO 纳米棒阵列交错而成，每个 TiO 纳米棒核上都有一个纳米结构的 CdS 壳作为界面层。在了解 TiO-CdS-Sb2S 系统中的界面相互作用和能带排列后，揭示了 CdS 界面层作为带弯曲空间间隔层的作用，它与 TiO 电子传输体和 Sb2S3 吸收体强烈相互作用，以提高电荷收集效率；此外，通过光照对带弯曲的 CdS 层进行空间电荷充电，并提出了一个光生界面偶极电场模型，用于理解在 CdS 界面层存在的情况下高 Voc。这项工作为设计高效无机异质结太阳能电池提供了概念性指导。
