Development of a new Schiff-base semiconducting material for thin film active device and analysis of its charge transport mechanism

Schiff-base compounds have rarely been employed in optoelectronics. Herein, we report the optical and electrical properties of a Schiff-base compound, 1,4-bis-(quinolin-6-yl iminomethyl)benzene (BQB), in detail. The electrical properties of BQB have been studied with a thin film made of it. The results of electrical conductivity and measurement of optical band gap of BQB encouraged us to examine its potential application in metal (Al)-semiconductor Schottky diode. I–V measurement of ITO/BQB/Al configuration illustrated its Schottky behavior with a moderate rectification ratio at applied bias potential of ±1.0 V. The characteristic diode parameters were obtained. The device showed a good ideality factor of 1.2 and low barrier height of 0.44 eV. Charge transport properties through the metal semiconductor junction, which is critical for device performance, were analyzed by space charge-limited current theory. In this regard, mobility–lifetime product, carrier density, density of states at Fermi level and diffusion length was estimated. The results show that this new Schiff-base compound has the potential for successful application in thin film semiconductor device.