High Performance PbS Colloidal Quantum Dot Solar Cells by Employing Solution-Processed CdS Thin Films from a Single-Source Precursor as the Electron Transport Layer

3 years ago

High Performance PbS Colloidal Quantum Dot Solar Cells by Employing Solution-Processed CdS Thin Films from a Single-Source Precursor as the Electron Transport Layer

Gavin J. Conibeer, Lin Yuan, Yicong Hu, Shujuan Huang, Gang Wang, Robert J. Patterson, Long Hu, Zhilong Zhang, Zihan Chen, Weijian Chen

CdS thin films are a promising electron transport layer in PbS colloidal quantum dot (CQD) photovoltaic devices. Some traditional deposition techniques, such as chemical bath deposition and RF (radio frequency) magnetron sputtering, have been employed to fabricate CdS films and CdS/PbS CQD heterojunction photovoltaic devices. However, their power conversion efficiencies (PCEs) are moderate compared with ZnO/PbS and TiO2/PbS heterojunction CQD solar cells. Here, efficiencies have been improved substantially by employing solution-processed CdS thin films from a single-source precursor. The CdS film is deposited by a straightforward spin-coating and annealing process, which is a simple, low-cost, and high-material-usage fabrication process compared to chemical bath deposition and RF magnetron sputtering. The best CdS/PbS CQD heterojunction solar cell is fabricated using an optimized deposition and air-annealing process achieved over 8% PCE, demonstrating the great potential of CdS thin films fabricated by the single-source precursor for PbS CQDs solar cells. A heterojunction PbS quantum dot solar cell with an efficiency over 8% is achieved by optimizing CdS electron transport layer deposited by a simple single-source precursor spin-coating process. The optimized band alignment of the device improves the short circuit current and fill factor.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/adfm.201703687