Visible-light induced photosplitting of water using solution-processed Cu2BaSnS4 photoelectrodes and a tandem approach for development of Pt-free photoelectrochemical cell

• Published in: Materials science in semiconductor processing Vol. 121
• Main Authors: Sharma, Akash, Sahoo, Pooja, Singha, Abhijit, Padhan, Subash, Thangavel, R.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2021
• Subjects: Pt-free photoelectrochemical cell; Spin coating; Sulfidation free; Thin films; Water splitting; Thin films; Water splitting; Pt-free photoelectrochemical cell; Spin coating; Sulfidation free
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2020.105433

In this present work, investigation on the physical and chemical properties of the quaternary Copper–barium–thiostannate (Cu2BaSnS4) compound was carried out. Cu2BaSnS4(CBTS) thin films were synthesized by using the cost-effective, sol-gel spin-coating technique without further sulfurization. The light-sensitive nature of CBTS was investigated by illuminating the thin films directly under AM 1.5G condition, resulting in an enhancement of 47% in terms of photocurrent density. The p-type nature was confirmed from the Mott Schottky analysis carried out in 0.5 M Na2Ssolution without illumination. A flat band potential value of 2.354 ±0.003 V vs. RHE along with a carrier density of 9.314 ×1019cm−3and Debye length of 0.288 nm were also obtained for the CBTS thin films. From Bode plots, the carrier lifetime of CBTS films was estimated to be 88 m s. Further Pt-free photoelectrochemical cells were fabricated by using ZnO nanorods as counter electrodes. From linear sweep voltammetry results, photocurrent density of −6.805 and −2.112 mA/cm2 at 0 V (vs. RHE) under illumination in the presence of Pt electrodes and ZnO Nanorods, respectively. Photoconversion efficiency of ∼10% and ∼4% were estimated for the CBTS thin film in the presence of Pt and ZnO counter electrodes. Thus the physical properties observed here indicate the suitability of solution-processed CBTS thin films in its further use for harvesting solar energy. [Display omitted] •A facile sulfurization free, solution-processed synthesis procedure was adopted for Cu2BaSnS4 was adopted.•We observe a significant enhancement of nearly 47% upon illumination, proving its credential as a photoabsorber.•The Pt-free photoelectrochemical cell resulted a photocurrent density of −2.112 mA/cm2 at 0 V (vs. RHE) under illumination.•CBTS thin films showed a photoconversion efficiency of ∼4% in presence of ZnO Nanorods as the counter electrode.