Adsorption Characteristics of Algan/Gan Heterojunction on Potassium Ions: First-Principles and Tcad Study

Understanding the adsorption behavior of a specific ion on AlGaN surface and the eventual effect on AlGaN/GaN heterostructure interface is the key to obtain high-performance nitride sensors. In this paper, the sensing of potassium ions on AlGaN/GaN heterojunction HEMT devices was realized by surface potential effect, the change of material properties caused by adsorption of potassium ions on AlGaN surface was obtained by using the first principle based on density functional theory (DFT) calculations, and the value of change of the forbidden band width of the material after adsorption of one potassium ion was obtained to be 0.05ev, and then the HEMT devices were constructed by using the software of TCAD, which corrected the material properties and obtained its output current became larger by 0.1789mA, thus realizing the sensing of potassium ions, indicating that the AlGaN/GaN heterojunction HEMT device can recognize the sensing of potassium ions through the surface potential effect, which provides a theoretical basis for the realization of potassium ion sensing based on GaN sensors.