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First‐Principles Study of the Effects of Interstitial H and Point Vacancies on the p‐Type of Conductive Properties of Be/Mg/Ca‐Doped GaN
Author(s) -
Yin Xiang,
Hou Qingyu,
Chen Hao
Publication year - 2021
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.202100023
Subject(s) - pseudopotential , doping , density functional theory , materials science , type (biology) , gallium , condensed matter physics , chemistry , physics , computational chemistry , optoelectronics , metallurgy , ecology , biology
Obtaining a reliable positive‐type (p‐type) GaN semiconductor is difficult because of the unipolarity of GaN. This difficulty is one of the bottlenecks restricting the development of GaN‐based optoelectronic devices. To address this problem, this paper adopted the method of generalized gradient approximation (GGA) plane wave ultrasoft pseudopotential based on the framework of density functional theory to construct Ga 35 MN 36 , Ga 34 MN 36 , and Ga 34 MH i N 36 (M = Be/Mg/Ca; H i = interstitial hydrogen) models. Ga 35 MN 35 and Ga 35 MH i N 35 (M = Be/Mg/Ca) models were also constructed. Results of our calculations indicated that the Ga 35 MN 35 and Ga 35 MH i N 35 (M = Be/Mg/Ca) models cannot achieve a p‐type doping system. Furthermore, the formation energy of Ga 34 MN 36 and Ga 34 MH i N 36 (M = Be/Mg/Ca) systems was greater under Ga‐rich conditions than that under N‐rich conditions, indicating that both doping systems more readily formed and had a more stable structure under N‐rich conditions. Moreover, the formation energy of Ga 34 MH i N 36 (M = Be/Mg/Ca) system was lower than that of Ga 34 MN 36 (M = Be/Mg/Ca) system, and the existence of interstitial H proved to be beneficial to the improvement in system stability. The Ga 34 CaH i N 36 system had the largest hole mobility and the best conductivity. Therefore, the Ga 34 CaH i N 36 system is an ideal material for the application of conductive GaN devices. This study provides guidance into the preparation of p‐type conductive GaN materials.