Effect of annealing on InGaN/GaN multiple quantum wells

The effect of annealing on InGaN/GaN multiple quantum wells (MQW) grown by using metalorganic chemical vapor deposition is studied. The samples were annealed at 900 .deg. C for 10, 20, 30, 40, and 50 min, in a furnace with a N2 atmosphere. The variation of the period in the quantum well with increasing annealing time was observed by analyzing the satellite peaks in the high-resolution X-ray diffraction pattern. Also, the photocurrent and the photoluminescence spectral peaks were red-shifted and blue-shifted, respectively, annealing time. The red-shift is attributed to a decrease in the quantized energies due to a reduction in the inhomogeneity of the indium content in the QW. The blue-shift can be understood as being due to on increase in the quantized energies for the ground state due to the interdiffusion of In and Ga atoms across the barrier/QW interface, which leads to a change in the potential profile of the conduction and the valence bands.