Suppression of GaInN/GaN multi-quantum-well decomposition during growth of light-emitting-diode structure

Growth of GaN-based light-emitting-diode (LED) structures with GaInN/GaN multi-quantum wells (MQWs) has been explored by metalorganic chemical vapor deposition. GaInN/GaN MQW structures were found to decompose during the subsequent growth of a Mg-doped GaN top layer. This was prevented by adding 5% hydrogen in the growth of the GaN quantum barrier (QB) layer. Photoluminescence (PL) analysis of the grown GaInN/GaN MQW shows a PL peak shift caused by a reduction of the GaInN quantum well (QW) thickness. To prevent the variation of the GaInN QW thickness, a GaN cap layer with varying thickness has been inserted between the GaInN QW and the GaN QB layer. Both strong PL intensity and suppression of the peak shift were obtained for a 1-nm-thick GaN cap layer.