CHARGE CARRIER DYNAMICS IN THE PICOSECOND TIME DOMAIN IN PHOTOELECTROCHEMICAL CELLS

An experimental method is described for measuring photocurrents in electrochemical systems with 100 ps rise time and 20 nA sensitivity. Three experimental results that were obtained with this technique are described. Firstly, the time-resolved diffusion transient of screened holes was measured as the photocurrent that arises at the n-GaAs/electrolyte interface. Secondly, a surface charge-transfer complex with a life time of 450 ps was detected as the intermediate in rhodamine B sensitized hole injection into an anthracene crystal. Thirdly, excitation of the 395 cm** minus **1 vibration in the anthracene molecule was found to be a very efficient accepting mode in the case of extremely fast hole transfer in the anthracene crystal at room temperature.