Electronic transport properties of 1-(p-R-phenacyl)-4-{[(1'-ethylcarboxylate)-(3'-p-R'-phenacyl)] -7'-indolizinyl}pyridinium bromides in thin films

The temperature dependences of electrical conductivity, σ, and Seebeck coefficient, S, for some new pyridium monoquaternary salts derivatives, 1-(p-R-phenacyl)-4-{[(1'-ethylcarboxylate)-(3'-p-R'-phenacyl)] -7'-indolizinyl}pyridinium bromides have been studied. The film samples (d = 0.08-0.28 μm) have been deposited onto glass by an immersion technique (dimethylformamide was used as a solvent). The investigated compounds behave as typical p-type polycrystalline semiconductors. The activation energy of electrical conduction ranged between 0.65 and 1.72 eV, while the ratio of charge carrier mobilities laid in the range (0.60-0.83). The model based on band gap representation is suitable in explaining the electronic transport in present compounds in the higher temperature range (385-500 K)