Quantitative measurement of In fluctuation inside MOCVD InGaN QWs

Using strain analysis on high resolution transmission electron microscopy (HREM) images of InGaN QWs, we determine the In composition changes inside the layers. The analysed samples were nominally grown with 17% In composition. Inside these QW layers, the In composition is never found to be homogeneous. Individual clusters with In composition up to 45% instead of the nominal 17% were identified. Such areas are 2 nm high and 3 nm wide.