The Characterization of P-Type Silicon Decorated by Phosphorus Doped Tungsten Disulfide (WS2-xPx) as a Photocathode for Solar Water Splitting
Hsin-Chin Yu1*, I-Shiou Wu1, Yu-Chen Lin1, Shu-Fen Hu*1
1Department of Physics, Nation Taiwan Normal University, Taipei, Taiwan
* Presenter:Hsin-Chin Yu
Green Energy has increased in importance and significance in our economy in the past few years. Using semiconductor for solar water splitting is regarded as a way to create clean and renewable energy. A semiconductor material, known as silicon, has a great band position to produce hydrogen in water splitting process. Even though Si has great band position, there are still two issues in using this material for solar water splitting process. The first is that silicon is less kinetic of photo-generated carriers because of the small band gap. The second is the bare silicon can only absorb 34% solar energy. To solve these problems, several researches have shown that transition metal dichalcogenides are an efficient catalyst for water splitting. To increase light absorption, we apply surface roughness process to produce pyramid surface structure for reducing the reflection efficiency of silicon chips.
In this study, we use tungsten disulfide doped phosphorus as an Earth-abundant co-catalyst via drop-casting method decorate on the morphology like micro-pyramid of silicon for electrochemical and photoelectrochemical hydrogen production. The micro-pyramid is made by strong alkaline solution wet etching, owing to its morphology can enhance the light absorption. Use Raman spectra to confirm whether there is a phosphorus doped in Tungsten disulfide. The results have shown that decorate WS2-xPx on p-type Si as a photocathode exhibit high-performance of photocurrent-density and high-efficiency hydrogen evolution reaction (HER). The current density reach to -18.7 mA/cm2 at 0 V vs RHE and onset potential of 0.15 V vs RHE.

Keywords: Water splitting, Hydrogen evolution, Tungsten disulfide, Catalysts, Transition metal