Effect of Single Particle-Particle Interface on Photoelectrodes Performance

Abstract

Light-to-energy conversion is an encouraging approach to overcome the energy crisis and generate clean fuels (e.g., hydrogen) and electricity. Photoelectrochemical cells (PECs) and photovoltaics (PVs) are two main technologies that have been used extensively for such conversion. PECs and PVs are consisting of a semiconducting electrode as light absorber materials. Traditionally, PECs and PVs are fabricated by accumulating a film of nanostructured semiconductors in which, the photogenerated charge carrier (e.g., electrons) has to pass through several nanostructures’ interfaces. We designed a sophisticated photoelectrochemical cell setup and used a focused laser beam (i.e., ~400 nm) to locally generate charge carriers at different location, i.e., before and after particle-particle interface. Our sub-particle, single-interface photocurrent measurements revealed that indeed there is a noticeable photocurrent drop per interface. Thus, such quantitative metric should be considered for surface and interface engineering of photoelectrode in PECs and PVs.