Early stage growth process of dinaphtho[2, 3-b:2', 3'-f]thieno[3, 2-b]thiophene (DNTT) thin film

Early stage growth process of Dinaphtho[2, 3-b:2', 3'-f]thieno[3, 2-b]thiophenes (DNTTs) thin film was investigated using grazing incidence X-ray diffraction (GIXD) and surface morphology analysis using atomic force microscopy (AFM). The thin film growth conditions were controlled by the slow deposition method. The vertical orientation of DNTT was confirmed from the first layer growth by GIXD. The morphologies of first layer grains were universal in the growth rate range of 0.155 ML/min - 0.017 ML/min. In addition, the dependence of the nuclei density on the deposition flow rate indicates that the number of molecules required for nucleation is 2 molecules (dimers). This result indicates that fewer molecules are sufficient for nucleation in the case of DNTT compared to the pentacene thin film growth on SiO2.