XRD Analysize PTCDA Film Evaporatived on p-Si (110) Substrate

We used X-ray diffraction(XRD) analyze the property of each PTCDA film which deposited on p-Si(110) substrate in different technological parameter. the result of XRD analysis showed PTCDA thin film which deposited on p-Si(110) substrate growth pattern is crystal. With the increase of the thickness of PTCDA film, there appears α-PTCDA and β-PTCDA in the thin film at the same time. For the sample that PTCDA film evaporatived on p-Si (110) substrate when substrate temperature is 50°C, diffraction peaks is at 2θ≈27.50, diffraction peak position corresponds to the monoclinic (102) lattice plane, PTCDA molecular plane almost parallel to the substrate. For the sample that PTCDA film evaporatived on p-Si (110) substrate when substrate temperature at 100°C, PTCDA molecular grow nearly perpendicular to the surface of substrate. When substrate temperature is 150°C, there is the same situation. The sample is 150°C, the decrease of diffraction peaks intensity may attributed to PTCDA molecular plane in some areas change relative to the substrate plane. With the Increase of the temperature, Increase in Peak position is 0.1, this is attributed to the Increase in the Proportion of β-PTCDA. Peak width at half decreases from 0.494 when substrate temperature is 50°C to 0.09 when substrate temperature is 150°C. And peak width at half decreases with the peak intensity decreases.