2D material 2DEG density AlGaN/GaN CMOS power amplifier IC Green's function InAlN/GaN heterostructure L-shaped tunnel field-effect-transistor MISHEMT Mott transition PC1D PECVD UAV UV irradiation ZnO films ZnO/Si atomic layer deposition (ALD) back current blocking layer (BCBL) band-to-band tunneling bandgap tuning bismuth ions bistability charge injection conditioned reflex conduction band offset conductive atomic force microscopy (cAFM) conductivity corner-effect cross-gain modulation current collapse dielectric layer