The length of vertically oriented nanorods in the Sb2Se3-H thin film is longer than that of the Sb2Se3-L thin film, which is in good agreement with observations in the cross-sectional SEM images (Figure ). However, the Sb2Se3-H thin film exhibits a denser array of nanorods compared to its counterpart, as evident from the top-view SEM images. For the Sb2Se3-L thin film, the diameter of the vertical nanorods is smaller compared with that of the Sb2Se3-H thin film. By analyzing more than 200 typical nanorods from the top-view SEM images, the statistical distributions of the diameter of the Sb2Se3 nanorods were obtained (Figure ). The mean diameter values for the Sb2Se3-L and Sb2Se3-H thin films are 202 ± 48 and 124 ± 28 nm, respectively. Such a considerable difference in the morphology of vertically oriented Sb2Se3 nanorods can be attributed to the surface energy-driven growth during the selenization process.