Growth delay in GaInN/GaN multi quantum wells

We have grown MQW (multi quantum well) structures under different growth conditions in a MOVPE reactor (AIXTRON 200RF). The combination of high resolution X-ray diffraction with TEM measurements allow the determination of structural parameters of the layered system. By a systematic variation of thickness of QW and V/III ratio we have observed a growth delay in period length (i.e. QW+barrier thickness). This growth delay of 70 s relates to missing thickness of approximately 1 nm. Based on the observation that the TMI (trimethyl indium) flux exhibits a linear relationship with the period length as well as to the indium concentration in the QW we present a model which explains the origin of this growth delay. Finally we compare these results to PL measurements.