Relation between Ga vacancies, photoluminescence, and growth conditions of MOVPE-prepared GaN layers

0562801 - FZÚ 2023 RIV CH eng J - Journal Article
Hospodková, Alice - Čížek, J. - Hájek, František - Hubáček, Tomáš - Pangrác, Jiří - Dominec, Filip - Kuldová, Karla - Batysta, Jan - Liedke, M.O. - Hirschmann, E. - Butterling, M. - Wagner, A.
Relation between Ga vacancies, photoluminescence, and growth conditions of MOVPE-prepared GaN layers.
Materials. Roč. 15, č. 19 (2022), č. článku 6916. E-ISSN 1996-1944
R&D Projects: GA MŠMT LM2018110; GA ČR(CZ) GF22-28001K; GA MŠMT(CZ) EF16_019/0000760
Grant - others:AV ČR(CZ) PAN-20-19; OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Program: Bilaterální spolupráce
Institutional support: RVO:68378271
Keywords : GaN * defects * positron annihilation spectroscopy * photoluminescence * MOVPE
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 3.4, year: 2022
Method of publishing: Open access

A set of GaN layers prepared by MOVPE under different technological conditions were investigated using variable energy positron annihilation spectroscopy (VEPAS) to find a link between technological conditions, GaN layer properties, and the concentration of Ga vacancies (VGa). In case of TEGa precursor, the formation of VGa was significantly influenced by the type of reactor atmosphere N2 or H2, while no similar behaviour was observed for TMGa. VGa formation was suppressed with increasing temperature for growth from TEGa. PL results show that yellow band luminescence in GaN is likely not connected with VGa, additionally, increased VGa concentration enhances excitonic luminescence. The probable explanation is that VGa prevent the formation of some other highly efficient nonradiative defects. Possible types of such defects are suggested.
Permanent Link: https://hdl.handle.net/11104/0334994