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Triple‐Site Dopant–Defect Complexes in Mg–H‐Codoped GaN: First‐Principles Identification
Author(s) -
Huang Menglin,
Li He,
Chen Shiyou
Publication year - 2021
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.202000723
Subject(s) - dopant , acceptor , doping , materials science , limiting , photoluminescence , band gap , crystallography , chemistry , optoelectronics , condensed matter physics , physics , mechanical engineering , engineering
There are dozens of double‐site and triple‐site dopant–defect complexes in Mg–H‐codoped GaN that can compensate the Mg Ga acceptor and thus limit p‐type conductivity; however, their properties have not been systematically studied. Using first‐principles calculations, herein, it is found that the well‐known double‐site complexes Mg Ga –V N and Mg Ga –H N can still act as donors, although they are already donor–acceptor‐compensated complexes. Therefore, they can compensate another Mg Ga acceptor and form the triple‐site complexes Mg Ga –Mg Ga –V N and Mg Ga –Mg Ga –H N , which have never been reported. The formation energies of the two triple‐site complexes can be low, especially in Ga‐rich and n‐type GaN, so they have non‐negligible concentration and thus play an important role in limiting the p‐type conductivity. The Mg Ga –Mg Ga –V N complex produces a defect level that can not only induce nonradiative electron–hole recombination, but also give rise to a red and broad photoluminescence band at 1.76 eV, providing another explanation for the red band observed in heavily Mg‐doped GaN. These triple‐site dopant–defect complexes should be taken into account in future study of defects in GaN and related semiconductors.