Majority Charge Carrier Transport in Particle-Based Photoelectrodes

Abstract

The interparticle charge transfer of particle-based photoelectrodes was investigated using a particle-based LaTiO2N photoelectrode as model system. The thickness-dependent front- to back-side illumination photocurrent ratio was measured and compared to the numerical photogenerated current ratio. This comparison suggested the presence of majority charge carrier transport limitations and estimated that only a particle-based film thickness of 450 nm was contributing to the photocurrent. We introduced three different theoretical interparticle charge transfer mechanisms and implemented their respective equations in a computational model. The calculated photocurrent–voltage curves were compared to experimental data and proved that interparticle charge transfer is negligible. Only the particles in direct contact with the fluorine-doped tin oxide glass substrate were contributing to the photocurrent. Thus, more efficient particle-based photoelectrodes should incorporate efficient conductive networks connecting pa...