Nano-clustering anomalies in InGaN/GaN multiple quantum well structures

This chapter examines the morphology and composttion of InxGa 1n_xN/GaN multiple quantum well structures and their sensitivity to electron beam damage. Exposure to relatively low incident beam illumination, corresponding to current densities at the specimen of ~100A/cm² cumulated in a significant redistribution of indium within the multiple quantum wells. The findings highlight the need for caution when interpreting analytical data obtained from InGaN/GaN multiple quantum wells studied in the transmission electron microscope. Particular attention has been directed towards the development of high-brightness light emitting diodes and room temperature laser diodes based on InGaN/GaN single and/or multiple quantum well structures. A definite modulation in the strain contrast was observed as a function of exposure time, apparent as regions of increasing dark contrast along the quantum wells. The indium rich quantum wells are shown in bright contrast due to their higher average atomic number.