• The adsorption energy, surface migration potential, and Ehrlich-Schwoebel barrier of an indium adatom on reconstructed vicinal GaN(0001) surfaces during metalorganic chemical vapor deposition were clarified by ab initio calculations. • It was found that an indium adatom sufficiently migrates across atomic steps on the growth surface during MOCVD and probabilistically stabilizes at sites adjacent to nitrogen-terminated step edges. • The surface migration potentials of indium adatoms, which are crucial yet previously missing surface properties necessary for simulating InGaN MOCVD on vicinal GaN(0001), were obtained. The study investigates the adsorption energy, surface migration potential, and Ehrlich-Schwoebel barrier (E ESB ) of an indium adatom on reconstructed vicinal GaN(0001) surfaces during metalorganic chemical vapor deposition (MOCVD) using ab initio calculations. Under typical MOCVD conditions, surface reconstruction with excess gallium (coverage of 25%) has been expected to appear on the terraces of vicinal GaN (0001). Additionally, Step A, with weak Ga-Ga bonds, and nitrogen-terminated Step B coexist on the vicinal GaN(0001) tilted toward 10-10. On the terrace, the activation energy for indium migration is estimated at 0.13 eV. The activation energy for indium migration from the upper to the lower terrace, E ESB , is 0.98 eV crossing Step A and 0.72 eV crossing Step B. An indium adatom prefers to stabilize at the sites adjacent to Step B, forming an In-N bond with a nitrogen atom at the step edge and two In-Ga bonds with gallium atoms on the lower terrace. The indium adsorption energy at the site adjacent to Step B is 0.34 eV lower than on the terrace. This study also analyzes the indium migration potentials on the vicinal GaN(0001) tilted toward 11-20. Consequently, we obtain the surface migration potentials of indium adatoms, which are crucial yet previously missing surface properties necessary for simulating InGaN MOCVD on vicinal GaN(0001). Migration pathway of indium on vicinal GaN(0001). Surface reconstruction is considered, and pre-adsorbed Ga (Ga ad ) exists on the terrace. On this surface, indium is stabilized at sites adjacent to Step B, and the other surface properties were also clarified.
Nishizawa et al. (Sat,) studied this question.