Temperature Dependent Study of Carrier Diffusion in Photon Enhanced Thermionic Emission Solar Converters

Photon Enhanced Thermionic Emission (PETE) is a novel concept in solar energy<br /> conversion, which can efficiently harvest solar energy at elevated temperatures. However, the temperature dependence of material parameters has not been clearly stated so far. In this study, a model for carrier transport is presented based on one dimension diffusion equation. Material data of GaAs are used to testify the temperature impact on material parameters. We find that for higher doped p-type GaAs which is suitable for PETE cathode material, its electron diffusion length shows weak temperature dependence. Carrier transport efficiency can be boosted by optimizing the geometry of the cathode and the optical parameters of the material. Finally, we propose a design of reflective mode cathode with reflective back surface and nanostructure emissive surface for PETE application