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Hole Trapping at Acceptor Impurities and Alloying Elements in AlN
Author(s) -
Lyons John L.,
Van de Walle Chris G.
Publication year - 2021
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.202100218
Subject(s) - materials science , acceptor , trapping , impurity , metastability , doping , nitride , aluminium , ionization , chemical physics , atomic physics , condensed matter physics , ion , optoelectronics , nanotechnology , chemistry , physics , metallurgy , ecology , organic chemistry , layer (electronics) , biology
Hole localization is a root cause of difficulties in p‐type doping of aluminum nitride. Herein, the stability of localized holes in AlN and their susceptibility to self‐trapping within bulk material or in the presence of isovalent elements and acceptor impurities are calculated. It is found that self‐trapped holes are metastable in bulk AlN, and also exhibit a very low barrier to detrapping. However, holes become trapped in the presence of acceptor impurities as well as isovalent elements such as B, In, and Sc, and may contribute to the broad luminescence observed in AlN alloys. It is also found that hole trapping contributes to the large ionization energies for acceptors in AlN. Most acceptors can also trap a second hole, becoming positively charged and further exacerbating difficulties in doping aluminum nitride p type. The stability of trapped holes is found to scale with atomic size mismatch to Al.