By introducing ZnS between Cu(In, Ga)(S,Se)2 (CIGS) and the CdS, we greatly improved the photoelectrochemical (PEC) performance of the CIGS photocathode for hydrogen evolution. Chemical and structural analysis reveals that the enhanced performance is due to additional band bending driven by in-diffusion of Zn into the CIGS and suppression of nonradiative recombination. The improved onset potential of CIGS photocathode was exploited by building a tandem device with a perovskite absorber for bias-free water splitting. A PEC device with a solar-to-hydrogen conversion efficiency exceeding 9% (the highest among PEC cells including a CIGS photocathode) with a stable operation of 6.5 h is demonstrated.
Bibliographical noteFunding Information:
This research was supported by the Nano-Material Technology Development Program (Green Nano Technology Development Program) through the National Research Foundation (NRF) funded by the Ministry of Education, Science and Technology (No. 2018M3A7B4065662) and the NRF grant funded by the Korean Government (NRF-2017M2A2A6A01071012 and NRF-2018R1A5A1025594). The work at Kyungpook National University was supported by the Bio & Medical Technology Development Program of the NRF funded by the Ministry of Science and ICT (2017M3A9G8083382). The work at Sejong University is supported for data analysis and characterization from the NRF of Korea funded by the Ministry of Science, ICT (NRF-2017R1A4A1015022).
© 2020 American Chemical Society.
- Cu(In, Ga)(S, Se) photocathode
- perovskite solar cell
- surface band bending
- unassisted solar water splitting
ASJC Scopus subject areas
- Chemical Engineering (miscellaneous)
- Energy Engineering and Power Technology
- Materials Chemistry
- Electrical and Electronic Engineering