(351d) Engineering the Interface to Improve the Efficiencies of Insulator-Protected Semiconductors for Photoelectrochemical Cells

Recent improvements in solar fuels production efficiencies have been enabled by the development of protection schemes for low bandgap semiconductors that would otherwise be unstable in the harshly oxidative environment of an electrochemical cell. One common protection strategy incorporates an insulator layer placed between a metal electrocatalyst and semiconductor. Recent research has shown that the characteristics of the insulator layer have a large effect on the overall efficiency of a photoelectrochemical cell. In this contribution, we will provide experimental evidence that demonstrates how by tuning the properties of the insulator layer we can better control charge transfer across the interface in order to improve efficiencies. We will also present a model to describe the insulator layer’s effect on charge transfer mechanisms. Provided with these modeling insights, we will discuss which experimental systems can benefit from the most from insulator tuning in order to expand the flexibility of material selection for a photoelectrochemical device.