The influence of light intensity on photo-electrochemical cells (PECs) consisting of an n-type strontium titanate (SrTiO₃)
photoanode and nickel cathode in potassium hydroxide electrolyte is studied. The band levels of an electrolyte metalsemiconductor-electrolyte system are presented and the effect of different light intensities on the energy levels is investigated. Photocurrent density, quantum efficiency, and open circuit potential measurements are performed on the processed PECs under different light intensities (375 nm). It is demonstrated that a threshold value of the light intensity has to be reached in order to obtain positive photo activity and that beyond this value the performance remains nearly constant.