XPS NEXAFS 3 HEMT 2 III-V semiconductors 2 Sensor 2 Transistor 2 X ray photoelectron spectroscopy 2 Zwitterion 2 2-dimensional electron gas 1 ADSORPTION 1 AMINO-ACIDS 1 AP-MOVPE 1 Adatoms 1 Adsorption 1 AlGaN/GaN heterostructures 1 Alloy 1 Alloying 1 Alloying effect 1 Aluminum 1 Aluminum gallium nitride 1 Amino acids 1 Atmospheric pressure 1 Au(1 1 1 ) 1 Benzotriazole 1 Benzotriazoles 1 Carboxylation 1 Chemical and biological sensing 1 Computation theory 1 Conductivity measurements 1 Copper adatoms 1