The movement of the Fermi level in heavily C doped GaN

Abstract

It is empirically well acknowledged that C doping makes GaN high-resistive. However, the detailed doping type and high-resistivity mechanisms of C doped GaN, which are extremely essential for GaN power electronics, still remain unclear. In this work, we clarify the mutative (from downward to upward) shift of the Fermi level and the n-type conductivity in heavily C doped GaN grown by MOCVD for the C concentration increases over a critical value, by combining photo-assisted KPFM and Seebeck coefficient measurements. We also discuss the reverse transition of Fermi level and ultimately n-type conductivity should be attributed to the donor-type compensation centers.

Electrochemical performance enhancement of MnO2 nanowires through silver incorporation for next-generation supercapacitors

“…It is ascribed to the fact that heavy doping causes pinning of the Fermi level near the surface of the electro-active material, resulting in energy barrier change across the electrode–electrolyte interface, thus increasing resistance in charge transfer. 88,89 Additionally, high doping leads to more scattering centers which also resists the charge transfer at the electrode–electrolyte interface. 90…”