Influence of GaN buffer layer under InGaN/GaN MQWs on luminescent properties

0505794 - FZÚ 2020 RIV NL eng J - Journal Article
Dominec, Filip - Hospodková, Alice - Hubáček, Tomáš - Zíková, Markéta - Pangrác, Jiří - Kuldová, Karla - Vetushka, Aliaksi - Hulicius, Eduard
Influence of GaN buffer layer under InGaN/GaN MQWs on luminescent properties.
Journal of Crystal Growth. Roč. 507, Feb (2019), s. 246-250. ISSN 0022-0248. E-ISSN 1873-5002
R&D Projects: GA MŠMT(CZ) LO1603; GA ČR GA16-15569S
EU Projects: European Commission(XE) 690599 - ASCIMAT
Institutional support: RVO:68378271
Keywords : low dimensional structures * V-pits * metalorganic vapor phase epitaxy * InGaN/GaN quantum wells * GaN buffer layer * scintillators
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 1.632, year: 2019
Method of publishing: Limited access
https://doi.org/10.1016/j.jcrysgro.2018.11.025

Although InGaN layers or InGaN/GaN superlattices are commonly used as efficiency improving buffers for LED structure production, there is still a controversy and active discussion about the mechanisms improving the luminescence properties of InGaN QWs grown above such buffers. In this manuscript it is shown that presence of In in the buffer layer is not the primary reason for photoluminescence improvement which can be also achieved by introduction of GaN buffer layer grown at lower temperature under nitrogen atmosphere. SIMS analysis suggests that low temperature buffer layer does not influence the impurity incorporation and hence the PL improvement is caused by suppressed contamination of MQW region grown above the low temperature buffer. AFM images for two samples that differ mostly in morphology however supports another explanation in which formation of larger V-pits is the main reason for the luminescence improvement.
Permanent Link: http://hdl.handle.net/11104/0297183