Light emitting diodes with InAs/GaAsSb self-assembled quantum dot layer embedded in GaAs

0396370 - FZÚ 2014 RIV CH eng J - Journal Article
Hazdra, P. - Oswald, Jiří - Hospodková, Alice - Hulicius, Eduard - Pangrác, Jiří
Light emitting diodes with InAs/GaAsSb self-assembled quantum dot layer embedded in GaAs.
Thin Solid Films. Roč. 543, Sept (2013), 83-87. ISSN 0040-6090. E-ISSN 1879-2731
R&D Projects: GA ČR GAP102/10/1201; GA ČR GA202/09/0676
Institutional research plan: CEZ:AV0Z10100521
Keywords : quantum dots * electroluminescence * metalorganic vapor phase epitaxy * InAs * GaAsSb * light emitting diodes
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 1.867, year: 2013

Luminescence properties of MOVPE grown LEDs with active InAs/GaAs QD layer covered by GaAsSb SRL were investigated at temperatures from 10 to 400 K. Results show that the use of GaAsSb SRL with up to 14% Sb strongly increases luminescence, redshifts the emission maximum up to 1.4 μm while keeping the type I transition, narrows the luminescence linewidth and keeps the separation energy between the ground and excited state as in InAs/GaAs QD LEDs without SRL. The ground state electroluminescence shows the typical Stranski-Krastanov dot temperature properties. The electroluminescence intensity of the ground and excited state transitions increases with temperature (up to 80 K) due to the thermal escape of electrons from the wetting layer which reduces radiative recombination via wetting layer states. The dominant mechanism responsible for the thermal quenching of electroluminescence at elevated temperatures is the escape of electrons from QDs to the GaAs barrier.
Permanent Link: http://hdl.handle.net/11104/0224172