Studies of MOVPE growth conditions for the improvement of GaInAsN on GaAs substrates for 1.3 μm laser emission

Metal organic vapor phase epitaxy (MOVPE) growth conditions for the preparation of GaInAsN/GaAs single quantum wells (SQW) have been investigated using tertiarybutylarsine (TBAs) and dimethylhydrazine (DMHy) as arsenic and nitrogen precursors, respectively. We found that a low reactor pressure is required to minimize the effect of the DMHy injection on the indium composition of GaInAsN alloys. We have also established that a high TBAs/III ratio results in a significant improvement of the crystal quality GaInAsN/GaAs SQWs when it is combined with a low growth rate and a low growth temperature. As a result of such optimisation, the photoluminescence (PL) intensity of SQWs emitting at 1.3 μm could be increased by one order of magnitude and the PL line width could be reduced by half compared with more standard conditions using a lower TBAs/III ratio. The lasing threshold of optimised GaInAsN lasers emitting at 1.24 μm could be reduced by a factor of 6. We achieved photoluminescence emission at wavelengths up to 1.35 μm and lasing at 1.26 μm with a threshold as low as 540 A/cm² for a cavity length of 1220 μm.