Gas source molecular-beam epitaxial growth of TlInGaAsN double quantum well light emitting diode structures and thallium incorporation characteristics

TlInGaAsN/GaAs double quantum well (DQW) structures were grown on GaAs (1 0 0) substrates by gas source molecular-beam epitaxy. It has been found that high Tl flux is needed for the incorporation of Tl into the films. Reduction in the temperature variation of electroluminescence (EL) peak energy has been observed by the addition of Tl into quantum well (QW) layers; −0.62 meV/K for the InGaAsN/GaAs DQW light emitting diodes (LEDs) and −0.53 meV/K for the TlInGaAsN/GaAs DQW LEDs. By replacing GaAs barrier layers with TlGaAs barrier layers, further reduction could be obtained; −0.35 meV/K for TlInGaAsN/TlGaAs DQW LEDs. SIMS measurements indicated that this improvement is caused by the increased incorporation of Tl into the QW layers.