MgPc organic semiconductor thin films growth and investigation of the properties for optoelectronic applications

The continuously increasing energy requirement of humanity has led to the exploration of alternative energy sources. Organic solar cells, which have many advantages, have attracted attention in the research of alternative energy sources. Within the scope of this thesis, organic semiconductor material MgPc thin films were prepared on n-type Si, p-type Si and corning glass substrates by chemical spray pyrolysis (CSP) technique. The structural and morphological properties of MgPc thin films were investigated by XRD, RAMAN and SEM analysis. XRD patterns showed that these MgPc thin films have monoclinic β-phase structure with 2Ɵ peak at 70 , which is %100 with oriented (100) direction. Using the XRD spectrum and using the Debye Scherrer formula, the particle sizes were calculated as 0.31 nm for n-Si/MgPc, 0.41 nm for p-Si/MgPc and 0.41 nm for corning / MgPc. Dislocation concentrations were calculated as 10.4 nm2 for n-Si/MgPc, 5.95 nm2 for p-Si/MgPc and 5.95 nm2 for corning/MgPc. Forcing values were calculated as 0.10 for n-Si/MgPc, 0.07 for p-Si/MgPc and 0.07 for corning/MgPc. All of the MgPc thin films examined at the range of 200-1800 cm-1 and exhibited the same RAMAN spectrum with determined 16 Raman active peaks. These peaks are the same as the other M-PCs and are consistent with the literature. When SEM images were examined, it was observed that thin films had growth in dendritic structure with a size of approximately 60 nm. When the cross section SEM image was examined, it was found that the organic semiconductor thin film that was enlarged was approximately thickness 0.5 µm. Current-voltage measurements were taken to examine the electrical properties of the heterostructures. The barrier height, ideality factor and saturation currents were calculated from the calculated basic diode parameters of MgPc thin film in the forward feed direction. For n-Si/MgPc the barrier height was calculated as 0.78 eV, ideality factor 8.04 and saturation current 1.23 E-9. For p-Si/MgPc the barrier height was calculated as 0.64 eV, ideality factor 4.03 and saturation current 1.22 E-6. When the photosensitivity results were examined, the sensitivity of n-Si/MgPc thin film to light was observed to be about 100 times, whereas the sensitivity of p-Si/MgPc thin film to light was observed as 10 times.