Comparison of the Spatial and Temporal Photoluminescence Dynamics in InGaN/GaN at 365 nm and 430 nm Excitation

InGaN/GaN optical devices have emission wavelengths that cover the entire visible light range, depending on the indium composition ratio. However, a decrease in optical efficiency is known for high‐concentration indium samples (green luminescence). In these samples, luminescence is less uniform and photoluminescence instabilities (blinking) have also been reported. Although the luminescence mechanism of the blinking phenomenon has not yet been clarified, a qualitative explanation depicts the phenomenon related to the presence of dislocations. To examine these problems, this article reports how blinking change when stimulated at two different wavelengths, one that excites only the InGaN layer (442 nm), the other both (365 nm). In the case of simultaneous InGaN/GaN excitation, a larger number of blinking points are observed confirming several previous studies, whereas in the case of selective InGaN excitation, a noticeable photoluminescence uniformity and the reduction of blinking sites, in their size, contrast or even complete disappearance of them. This may be attributed to a simpler recombination process, where less traps and recombination pathways are available. On the contrary, the simultaneous excitation produces a complex recombination that uses intricate energy pathways through traps that are not involved by selective excitation. This results in a highly contrast of the photoluminescence and prominent localized blinking.