Effect of negative surface energy on nanocrystal morphology

One-dimensional materials, such as nanowires, nanotubes, and nanobelts, exhibit special optical and electrical properties owing to their high specific surface area and quantum confinement effect, and thus have wide application prospects. However, the surface energy of one-dimensional materials has caused some confusion in the past. In this work, we develop a model based on the thermodynamics, which can be used to explicitly predict the evolution of morphologies in different environments given its orientation-dependent surface free energy is negative. It is found that the negative surface energy would cause the increase of the interface and induce the bulk phase to nanowires. Our computations agree well with previous studies where applicable. (paper)