Formation of Ga vacancies in MOVPE prepared GaN layers

0568265 - FZÚ 2023 RIV DE eng A - Abstrakt
Hospodková, Alice - Čížek, J. - Hájek, František - Hubáček, Tomáš - Dominec, Filip - Kuldová, Karla - Liedke, M.O. - Butterling, M. - Wagner, A.
Formation of Ga vacancies in MOVPE prepared GaN layers.
Abstract book of the International Conference on Metalorganic Vapor Phase Epitaxy /20./ - ICMOVPE XX. Stuttgart: University of Stuttgart, 2022 - (Jetter, M.; Scholz, F.). s. 28-28
[International Conference on Metalorganic Vapor Phase Epitaxy ICMOVPE XX /20./. 10.07.2022-14.07.2022, Stuttgart]
Institucionální podpora: RVO:68378271
Klíčová slova: MOVPE * GaN * vacancies * positron annihilation spectroscopy
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)

Set of GaN layers prepared by MOVPE under different technological conditions were investigated by Variable energy positron annihilation spectroscopy (VEPAS) to find a correlation between technological conditions, GaN layer properties and VGa formation. VEPAS is unique and irreplaceable method to get information about VGa concentration in thin epitaxial layers. Dissimilar correlations between technological parameters and VGa formation were observed for layers grown from TEGa and TMGa precursors. In case of TEGa formation of VGa was significantly influenced by type of reactor atmosphere (N2 or H2), while no similar behaviour was observed for growth from TMGa. Formation of VGa was suppressed with increasing temperature for the growth from TEGa. On the contrary, enhancement of VGa formation was observed for growth from TMGa with cluster formation for the highest temperature of 1100°C. From the correlation of PL results with calculated VGa concentration it can be concluded, that yellow band luminescence is not connected with VGa in GaN and additionally, increased VGa concentration enhances excitonic luminescence. Probable explanation is that VGa prevents formation of some other highly efficient nonradiative defect.
Trvalý link: https://hdl.handle.net/11104/0339595