Correlation between yellow emission and misoriented structure in GaN epilayers

Abstract

A strong relationship between misoriented structure and yellow luminescence (YL) was found from the X-ray diffraction (XRD) and the photoluminescence measurements of GaN films grown by using radio-frequency induction-heated chemical vapor deposition and metal-organic chemical vapor deposition. YL was observed to be emitted from GaN films which contained peaks associated with the (10 (1) over bar0) and the (10 (1) over bar1) planes in their XRD spectra, and intensity variation of YL with some parameters, such as the growth temperature and the film thickness, had quite similar trends to that of the misoriented peak in XR.D. We suggest that this tendency is due to point defects acting as YL centers trapped at the interface between the (0001) oriented structure and an unintentional structure oriented in the [10 (1) over bar0] and the [10 (1) over bar1] directions.