Research on the Influence of the Interfacial Properties Between a Cu₃BiS₃ Film and an In_xCd_1−xS Buffer Layer for Photoelectrochemical Water Splitting

Abstract

The ternary compound photovoltaic semiconductor Cu3BiS3 thin film‐based photoelectrode demonstrates a quite promising potential for photoelectrochemical hydrogen evolution. The presented high onset potential of 0.9 VRHE attracts much attention and shows that the Cu3BiS3 thin films are quite good as an efficient solar water splitting photoelectrode. However, the CdS buffer does not fit the Cu3BiS3 thin film: the conduction band offset between CdS and Cu3BiS3 reaches 0.7 eV, and such a high conduction band offset (CBO) significantly increases the interfacial recombination ratio and is the main reason for the relatively low photocurrent of the Cu3BiS3/CdS photoelectrode. In this study, the InxCd1−xS buffer layer is found to be significantly lowered the CBO of CBS/buffer and that the In incorporation ratio of the buffer influences the CBO value of the CBS/buffer. The Pt‐TiO2/In0.6Cd0.4S/Cu3BiS3 photocathode exhibits an appreciable photocurrent density of ≈12.20 mA cm−2 at 0 VRHE with onset potential of more than 0.9 VRHE, and the ABPE of the Cu3BiS3‐based photocathode reaches the highest value of 3.13%. By application of the In0.6Cd0.4S buffer, the Cu3BiS3‐BiVO4 tandem cell presents a stable and excellent unbiased STH of 2.57% for over 100 h.

Spin-Coated CZTS Film with a Gradient Cu-Deficient Interfacial Layer for Solar Hydrogen Evolution

“…To avoid the influence of the surface capacitance, we measured the Mott−Schottky curves for all samples at five different frequencies (1000, 800, 600, 500, and 200 Hz), as shown in Figure 3b Schottky curve intersects the X-axis. 9,31,54,55 After the analysis, it is obtained that the V fb values of the CZTS, CZTS-8-8-8, CZTS-8-6-6, and CZTS-8-6-4 films are 0.5 V RHE (which is consistent with a previous report), 53 0.56 V RHE , 0.7 V RHE , and 0.66 V RHE , respectively. The data clearly show that with the introduction of the GCD-layer, the V f b of CZTS shifted positively.…”

Charge Separation Enhancement Enables Record Photocurrent Density in Cu2ZnSn(S,Se)4 Photocathodes for Efficient Solar Hydrogen Production

“…It is worth to mention that the obtained J ph value of device PC-2 is significantly higher than that of previously reported kesterites (i.e., including CZTS, CZTSe, and CZTSSe) thin-film photocathodes, also representing the top value for state-of-the-art chalcogenide-based photocathodes (Figure 1g; Table S1, Supporting Information). [3,5,10,11,14,15,[28][29][30][31][32] J-V curves associated to these devices in dark and continuous simulated sunlight irradiation are shown in Figure 1e, presenting a synchronous variation with strong correlation with CZTSSe film thickness. In addition, Figure 1f exhibits the as-calculated HC-STH conversion efficiencies.…”

Facile Aqueous Solution‐Gel Route toward Thin Film CuBi2O4 Photocathodes for Solar Hydrogen Production

“…[5] Chalcogenide semiconductors, for example, Sb 2 Se 3 , Cu 2 ZnSn(S,Se) 4 , Cu 2 CdSnS 4 , and Cu 3 BiS 3 , are another promising class, only mildly toxic and more earth-abundant. [10][11][12][13][14][15][16][17][18] The Sb 2 Se 3 is stable in neutral and basic aqueous solutions, even in acidic conditions upon protection with MoS x . [10,15] Half-cell STHs of Sb 2 Se 3 and Cu 2 ZnSn(S,Se) 4 are reported to reach 4.7% and 6.47%, respectively.…”