Tuning the composition of heavy metal-free quaternary quantum dots for improved photoelectrochemical performance

Journal: Journal of Materials Chemistry A (click here for full paper)

Authors: Cheng Liu, Xin Tong, Ali Imran Channa, Xin Li, Zhihang Long, Huijie Feng, Yimin You, Rui Wang, Feng Lin, Chang Fu Dee, Alberto Vomiero and Zhiming M. Wang

Contact details for further info: cfdee@ukm.edu.my

Summary:

Colloidal quantum dots (QDs) are promising building blocks towards the development of cost-effective and high-efficiency photoelectrochemical (PEC) cells. Unfortunately, the frequent use of QDs possessing heavy metals (e.g. Cd and Pb) in state-of-the-art QD-based PEC technologies is a major obstacle regarding their future commercial perspective. In this work, we synthesized heavy metal-free quaternary CuZnInS₃ (CZIS) with variable Cu : Zn ratios and fabricated corresponding QDs-PEC devices via a facile chemical bath deposition (CBD) technique. It is revealed that the tuned CZIS (1Zn) QDs (i.e. Cu : Zn ratio of 1 : 1) can result in optimized optical properties including enhanced quantum yield, suppressed nonradiative recombination and extended excitonic lifetime. Accordingly, as-fabricated CZIS (1Zn) QD-based photoanodes demonstrated increased charge transfer rate and decreased electron transport resistance for improved PEC performance. The results indicate that tuning the composition of heavy metal-free multinary QDs is one of the promising pathways to achieve eco-friendly and high-performance PEC systems for solar hydrogen production.