Tip-enhanced photoluminescence mapping of InGaN thin film

The photoluminescence from localized excitons in In0.25Ga0.75N was enhanced up to 6.6 times by approaching a gold nano-particle to nano-meter vicinity. Mapping images of enhanced photoluminescence and topological images were measured simultaneously with a spatial resolution of 100 nm. With an improved measurement system and selection of relatively flat area of the sample, we propose that the segregated metallic In droplet ought to play an important role for the present tip-enhance effect.