Several slice-like organic crystals grown by the physical vapor transport method: combining atomic force microscopy and X-ray diffraction to explore the characteristics of crystal formation

The surface morphologies and structural information of several slice crystals grown by the physical vapor transport (PVT) method were investigated using atomic force microscopy (AFM) and X-ray diffraction (XRD) analysis. Step-like structures were observed by AFM, corresponding with XRD results and the characteristics of layer-plus-island growth mode has been determined on the surface of a crystal grown from PVT, which is different from that of crystal thin film growth by molecular beam epitaxy ( MBE) and physical vapor deposition (PVD) in that the driving force depends mainly on the velocity of evaporating source materials, the temperature of the substrate and interactions between molecules. However, the main driving force for the formation of a slice crystal hanging inside the growth tubes from PVT without the influence of substrate depends solely on the interactions between the molecules in the crystal.