Hydrostatic pressure studies of photoluminescence from thick strained and unstrained epitaxial layers of cubic InGaN were performed. For strained In xGa1-xN films (x = 0.02-0.21) measured values of the pressure coefficients of emission energy, dEE/dP, showed (i) surprisingly low magnitude and (ii) a drastic decrease with increasing x. Moreover, for a relaxed layer of cubic In0.09Ga0.91N, a much higher dEE/dP is found than for a strained layer with the same composition. The proposed interpretation of the experimental results consists of two factors. First, a built-in biaxial strain due to lattice mismatch reduces dEE/dP. The nonlinear dependence of stress on strain has to be applied here. Second, the presence of In-rich fluctuations in InGaN layers causes light emission from regions of lower band gap, i.e., higher x value and lower dEE/dP, with respect to the regions with nominal In content.
|Number of pages||4|
|Journal||Physica Status Solidi C: Conferences|
|Publication status||Published - 2003 Dec 1|
|Event||5th International Conference on Nitride Semiconductors, ICNS 2003 - Nara, Japan|
Duration: 2003 May 25 → 2003 May 30
ASJC Scopus subject areas
- Condensed Matter Physics