Structural studies were made of InGaN epilayers of various thicknesses by means of X-ray diffraction, and revealed a strong dependence of the type and spatial distribution of extended crystalline defects upon layer thickness. The photoluminescence intensity for the samples was observed to increase with thickness up to 200nm and decreased for higher thicknesses, a result attributed to creation of dislocation loops within the epilayer. Correlation of physical properties with crystalline perfection open the way for optimized designs of InGaN solar cells, with controlled types and dislocation densities in the InGaN epilayers, a key requirement for realizing high photocurrent generation in InGaN.

Correlation of Crystalline Defects with Photoluminescence of InGaN Layers. N.Faleev, B.Jampana, O.Jani, H.Yu, R.Opila, I.Ferguson, C.Honsberg: Applied Physics Letters, 2009, 95[5], 051915