Zincblende to wurtzite transition during the self-catalyzed growth of InP nanostructures

We report on the structural and morphological evolution of indium phosphide nanostructures grown on InP(1 1 1)B via metalorganic chemical vapor deposition using liquid indium as the catalyst. The morphology and crystallinity are examined using scanning and transmission electron microscopies, electron backscattered diffraction, and selected-area electron diffraction. We observed two distinct shapes and crystal structures for InP grown at 385 and 400 °C using a P/In mole ratio of 100. At 385 °C, high-aspect-ratio, [1 1 1]-oriented, pure zincblende structured cones are obtained. In contrast, InP grown at 400 °C yielded low-aspect-ratio, [0 0 0 1]-oriented, pure wurtzite structured pillars. We attribute the change in morphology to a shift from In-catalyzed vertical growth to non-catalyzed lateral growth with increasing temperature. We suggest that the transition from zincblende to wurtzite structure observed at higher growth temperatures is due to the lowering of wurtzite nucleation barrier, a direct consequence of vapor phase growth kinetics.