Simrjit Singh

Project title: Ferroelectrically Controlled Tandem Photoelectrochemical/Photovoltaic Devices with Extended Light Harvesting for Efficient Unbiased Solar Hydrogen Generation

Host Institution: Eindhoven University of Technology (TU/e)

Host Supervisor: Prof. Jaime Gomez Rivas

Co-host Institution: Technical University of Munich (TUM)

Co-host Supervisor: Prof. Felix Deschler

Summary project: Solar hydrogen generation, a pathway to store solar energy in the form of chemical bonds, using tandem photoelectrochemical/photovoltaic (PEC/PV) devices, requires optimization of the front PEC electrode which is mainly limited by the low photocurrent. This project is targeted on the fabrication of PEC/PV tandem devices utilizing ultrathin 2D materials and conventional 3D semiconductors with appropriate bandgaps as PEC electrodes, and hybrid perovskite-based PV cell. Photocurrent in the PEC electrode will be maximized through the combined effects of optical engineering and ferroelectric polarization switching. Optical engineering by using hybrid conductive distributed Bragg reflector geometry and 3D ordered macro-mesoporous scaffold will be employed for enhancing light trapping and absorption in the PEC electrode. Also, ferroelectric polarization switching will be used to tune the band alignment for efficient charge carrier separation and migration leading to efficient unassisted solar water splitting. As a proof of concept, in-situ Terahertz spectroscopy will be employed to study the carrier dynamics in the devices. The present approach of fabricating PEC/PV tandem devices is expected to result in solar to hydrogen (STH) conversion efficiency exceeding 20% which can pave the way for developing low cost and highly efficient unassisted solar water splitting devices for commercial applications.