Lead halide perovskite solar cells (PSCs) are thought to be promising energy power suppliers because of their feasibility for high power conversion efficiency (PCE), light weight, and flexible architecture. The preparation of charge transporting layers at low temperature has been essential for high-performance and flexible PSCs. Recently, low-temperature-processed metal oxides have been a desirable material for charge transport and air stability for PSCs, instead of organic semiconductors. However, pristine metal oxides fabricated at low temperature have still precluded high performance of the device because of their low conductivity and large deviation in energy levels from the conduction band or valance band of the perovskite. Therefore, doping metals in the metal oxides has been considered as an effective method to endow suitable electrical properties. Herein, we developed a highly efficient electron transporting layer (ETL) comprising Li-doped SnO2 (Li:SnO2) prepared at low temperature in solution. The doped Li in SnO2 enhanced conductivity as well as induced a downward shift of the conduction band minimum of SnO2, which facilitated injection and transfer of electrons from the conduction band of the perovskite. The PCE was measured to be 18.2% and 14.78% for the rigid and flexible substrates, respectively. The high-performance and flexible PSCs could be potentially used as a wearable energy power source.
Bibliographical noteFunding Information:
This work was supported from the Technology Development Program to Solve Climate Changes ( 2015M1A2A2056824 ) and Global Frontier R&D Program on Center for Multiscale Energy System ( 2012M3A6A7054856 ) by the National Research Foundation under the Ministry of Science, ICT & Future Planning, Korea. This work was also supported by the KU-KIST Graduate School (R1435272) and KIST institutional programs.
© 2016 Elsevier Ltd.
- Flexible solar cell
- Low temperature and solution process
- Perovskite solar cell
- Tin oxide
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
- Electrical and Electronic Engineering