Dear Mainul Hossain ,

Hope you are well!

I investigated such devices within the scope of a project called hysolar when I was in Knig Saud University in Saudi Arabia.

I proposed models for the electrochemical water electrolyzer and photoelectrochemical electrolyzer.

If you search in my list of publications you will find these investigations.

For sure you will help you to proceed with your modeling project.

In summary I modeled the metal-electrolyte junction and the semicondcutor- electrolyte junctions similar to the p-n junction and I could workout SPICE models of the electrochemical cells and photoelectrochemical cells for water splitting.

Here the link of some of them:

Presentation The properties of electrodes and electrochemical cells for w...

Article “Basic structure of photo – electrochemical cathodes for hyd...

I will upload full text for the second paper such that you can benefit from it

as it was published in Ain Shams Engineering Journal

An integrated cell for the solar-driven splitting of water consists of multiple functional components and couples various photoelectrochemical (PEC) processes at different length and time scales. The overall solar-to-hydrogen (STH) conversion efficiency of such a system depends on the performance and materials properties of the individual components as well as on the component integration, overall device architecture, and system operating conditions. This Review focuses on the modeling- and simulation-guided development and implementation of solar-driven water-splitting prototypes from a holistic viewpoint that explores the various interplays between the components. The underlying physics and interactions at the cell level is are reviewed and discussed, followed by an overview of the use of the cell model to provide target properties of materials and guide the design of a range of traditional and unique device architectures.

Whatever simulation or modeling must be based on solid experimental data. Otherwise it would be reading the tea leaves.