High-Efﬁciency PbS Quantum-Dot Solar Cells with Greatly Simpliﬁed Fabrication Processing via “Solvent-Curing”
Kunyuan Lu, Yongjie Wang, Zeke Liu, Lu Han, Guozheng Shi, Honghua Fang, Jun Chen, Xingchen Ye, Si Chen, Fan Yang, Artem G. Shulga, Tian Wu, Mengfan Gu, Sijie Zhou, Jian Fan, Maria Antonietta Loi* and Wanli Ma*
1Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM) Soochow University 199 Ren-Ai Road, Suzhou Industrial Park Suzhou, 215123 Jiangsu, P. R. China
2Zernike Institute for Advanced MaterialsUniversity of GroningenNijenborgh 4, 9747 AG, The Netherlans
3Department of ChemistryIndiana UniversityBloomington, 800 E. Kirkwood Ave., Bloomington, IN 47405, USA
PbS quantum-dot (QD) solar cells are promising candidates for low-cost solution-processed photovoltaics. However, the device fabrication usually requires ten more times ﬁlm deposition and rinsing steps, which is not ideal for scalable manufacturing. Here, a greatly simpliﬁed deposition processing is demonstrated by replacing methanol with acetonitrile (ACN) as the rinsing solvent. It is discovered that ACN can effectively “cure” the ﬁlm cracks gener-ated from the volume loss during the solid-state ligand-exchange process, which enables the deposition of thick and dense ﬁlms with much fewer deposition steps. Meanwhile, due to the aprotic nature of ACN, fewer trap states can be introduced during the rinsing process. As a result, with only three deposition steps for the active layer, a CPVT-certiﬁed 11.21% power conversion efﬁciency is obtained, which is the highest efﬁciency ever reported for PbS QD solar cells employing a solid-state ligand-exchange process. More importantly, the simple ﬁlm-deposition processing provides an opportunity for the future application of QDs in low-cost printing of optoelectronic devices.