Photoelectrochemical conversion in a WO3 coated p-Si photoelectrode: Effect of annealing temperature

Abstract

The photoelectrochemical properties of a p-type silicon (100) electrode coated with tungsten oxide thin film were investigated as a function of annealing temperature. The variation in the annealing temperature affected the photocurrent of a WO3/p-Si electrode. A maximum photocurrent was obtained when the 500 Å WO3 thin film coated p-Si electrode was annealed at 350 °C for 1 h. A further increase in the annealing temperature and film thickness degraded the photocurrent. This can be explained in terms of electrical resistivity, carrier concentration, and depletion layer width. A WO3 thin film deposition on the p-Si shifted the flatband potential of the p-Si electrode by 0.3 V in the anodic direction, resulting in an improvement in conversion efficiency. These results are supported by x-ray diffraction, Auger electron spectroscopy, and capacitance measurements.

Enhanced photoelectrochemical properties of CuGa3Se5thin films for water splitting by the hydrogen mediated co-evaporation method

“…Similar phenomena have been reported in the literature. 17,21,22,37 This improvement in PEC properties by the utilization of a p-n heterojunction may result from the elongation of the charge depletion region through the introduction of a buffer layer (ZnS), restrained surface recombination due to reduction of surface defect states by CBD and the increased distance between the surface and the absorber (CGSe). To examine the stability of photocurrents generated by Pt/CGSe and Pt/ZnS/CGSe photoelectrodes, a constant potential measurement was performed at a negative potential of 0.1 V RHE .…”

Recent progress in photocathodes for hydrogen evolution

“…Metal oxides have been well studied as this kind of protecting layers before, and the early design was to prepare thick layers (>100nm), which could result in good corrosion protection but with poor charge transfer 116 . Thus, ultrathin layer (tens of nanometers or even several nanometers) with good band alignment, good conductivity, and high crystalline quality should be further explored to solve this confliction between charge transfer and corrosion prevention 87,[117][118][119][120] .…”

“…116 Thus, an ultrathin layer (tens of nanometers or even several nanometers) with good band alignment, good conductivity, and high crystalline quality should be further explored to solve this coniction between charge transfer and corrosion prevention. 87,[117][118][119][120] In future, one expects that the successful photocathode is to be made of composite material with designed structures. For visible light response and overall solar water splitting, semiconductor materials with appropriate bandgap and band edge positions should be chosen.…”

Photoelectrochemical water splitting: a road from stable metal oxides to protected thin film solar cells

“…21a). 312 In 1998 (ref. 313) they electron-beam evaporated 50 nm WO 3 on top of p-Si with 1-2 nm Pt as catalyst, and the role of a more efficient built-in eld is clearly observed when introducing WO 3 , with a better HER catalysis when Pt is incorporated (Fig.…”