PEPS Effect (Photoelectochemical Photocurrent Switching) - A phenomenon seen in semiconducting electrodes. It is defined as switching of photocurrent polarity on changes in photoelectrode potential and/or incident light wavelength. Konrad Szaciłowski i Wojciech Macyk were the first to describe it in their publication in 2006. The discovered phenomenon opens a wide variety of applications in construction of switches, logic gates and sensors based on chemical systems.