PbS-Based Quantum Dot Solar Cells with Engineered π-Conjugated Polymers Achieve 13% Efficiency
Muhibullah Al Mubarok, Febrian Tri Adhi Wibowo, Havid Aqoma, Narra Vamsi Krishna, Wooseop Lee, Du Yeol Ryu, Shinuk Cho, In Hwan Jung, Sung‐Yeon Jang
Abstract
While hole extraction is crucial for the external quantum efficiency of conventional n-i-p colloidal quantum dot (CQD) solar cells (CQDSCs), sulfur-passivated p-type CQDs (pCQDs) have been the best hole-transport material (HTM) to date. In this work, we developed organic π-conjugated polymers (π-CPs) that can achieve substantially improved HTM performance compared with conventional pCQDs. A weakly electron-withdrawing triisopropylsilylethynyl (TIPS) group was employed with a weak donor moiety, benzo[1,2-b:4,5:b′]-dithiophene (BDT), in the push–pull structured π-CPs to optimize the optoelectronic properties of the HTM. The CQDSCs using TIPS-containing π-CPs achieved a PCE (13.03%) substantially higher than those previously reported using pCQD (11.33%) or π-CPs (11.25%) owing to the improved charge collection efficiency near the photoactive CQD layer/HTM interface. To the best of our knowledge, our CQDSCs using TIPS-based π-CPs achieved the highest reported PCE among SSE-free CQDSCs.