Optically induced glide motion of misfit dislocations in InP/In1−xGaxAs1−yPy/InP double heterostructure

Abstract

Motion of misfit dislocations by optical excitation with Nd:YAG laser (1.06 μm) and Kr+ laser (0.647 μm) is studied by spatially resolved photoluminescence imaging technique in InGaAsP/InP double heterostructure wafers. Misfit dislocations are shrunken by optical excitation independently of both lattice mismatch and the light wavelength, though they are in the top InP layer but not in the InGaAsP layer. Misfit dislocations begin to move rapidly above a certain light intensity (threshold), and velocity exponentially increases with increase of the excitation intensity. The threshold decreases with decreasing thickness of the top InP layer. These results suggest that nonradiative recombination of excited carriers results in effective reduction of activation energy for glide motion of dislocation and that the carriers excited in the InGaAsP layer by Nd:YAG laser radiation leak into the top InP layer.