Influence of Vacancy Defect on Surface Feature and Adsorption of Cs on GaN(0001) Surface

Abstract

The effects of Ga and N vacancy defect on the change in surface feature, work function, and characteristic of Cs adsorption on a (2 × 2) GaN(0001) surface have been investigated using density functional theory with a plane-wave ultrasoft pseudopotential method based on first-principles calculations. The covalent bonds gain strength for Ga vacancy defect, whereas they grow weak for N vacancy defect. The lower work function is achieved for Ga and N vacancy defect surfaces than intact surface. The most stable position of Cs adatom on Ga vacancy defect surface is at T1 site, whereas it is at BGa site on N vacancy defect surface. The E ads of Cs on GaN(0001) vacancy defect surface increases compared with that of intact surface; this illustrates that the adsorption of Cs on intact surface is more stable.

First-Principles Insights into the Interface Chemistry between 4-Aminothiophenol and Zinc Phosphide (Zn3P2) Nanoparticles

“…The work function of the naked Zn 3 P 2 (001), (101), and (110) surfaces is predicted at 4.32, 4.79, and 4.75 eV, respectively, whereas the 4ATP-functionalized surfaces have calculated the work function of 4.07, 4.67, and 4.42 eV, respectively. The lowering of the work functions upon 4ATP adsorption can be attributed to the adsorption-induced electron density redistribution in the 4ATP-surface systems. − Besides, the adsorption acts to smoothen the surface electric charge distribution (the Smoluchowski effect) which lowers the work function. , …”

Characterisation of Cs ion implanted GaN by DLTS

“…Kampen et al are among the few authors who have investigated the adsorption of Cs on n-GaN [6]. Also, Ji et al used density functional theory (DFT) calculations to investigate the effects of Ga and N shallow vacancy defects on the adsorption of Cs on GaN [7]. In this study GaN was implanted with Cs ions with the view of studying the defects induced by this implantation process.…”