A Density Functional Theory Study of the Defective Aluminum Nitride Nanosheets as an Electrode Material for Supercapacitors

AbstractThe quantum capacitance characteristics of defective aluminum nitride nanosheets (AlNNS)are examined in this study with an emphasis on their possible application in supercapacitors.Using phonon spectrum analysis and cohesive energy calculations, we confirmed the structuralintegrity of the primitive cell. Our results show that thin monolayers with nitrogen (N),aluminum (Al), or Al-N deficits exhibit either narrow-bandgap semiconducting behaviour or metallic properties. Defect formation energy calculations suggest that the best choice is N-deficient AlNNS. New impurity states around the Fermi level arise as a result of under-coordinated atoms being present close to the defect. This study focuses on the potential application of defective aluminum nitride nanosheets (AlNNS) in supercapacitors byexamining their quantum capacitance properties. We verified the structural integrity of theprimitive cell using cohesive energy calculations and phonon spectrum analysis. According toour findings, thin monolayers with deficiencies in nitrogen (N), aluminum (Al), or Al-N exhibiteither metallic or narrow-bandgap semiconducting behaviour. Calculations of defect formation energy indicate that N-deficient AlNNS is the optimal option. The presence of under-coordinated atoms near the defect leads to the formation of new impurity states around the Fermi level.