Correlation between graded InAsP layer and photoluminescence intensity for 2200 nm CUTOFF In0.72Ga0.28As grown by chloride VPE

This paper reports the development of chloride VPE-grown 2200 nm cutoff In_0.72Ga_0.28As/InAs_yP_1-y (step layer) hetero-structures which are compositionally graded from y=0 to 0.4. The cross sectional structures of InAs_yP_1-y step layers were measured successfully, for the first time, using the near field photoluminescence line mapping (NF-PLLM) measurement technique. PL intensity from the In_0.72Ga_0.28As layer provides good correlation of device performance. The InGaAs PL intensity is strongly affected by the InAs_yP_1-y step layers. The step layers control the misfit dislocation structure. This paper presents the strong correlation between dislocation, measured by transmission electron microscopy (TEM) evaluation, and PL intensity. Furthermore, we will show that InAs_yP_1-y layers grown by Chloride VPE can control the InGaAs PL quality.