Synthesis of Phenanthro[9,10‐d]imidazoles and their Potential Applications in Solution Processable Bottom‐Gated OFETs

Abstract

Phenanthro[9,imidazole is synthesized by employing Radziszewski method and further functionalized through palladium catalyzed Suzuki cross-coupling reaction. Solution processable organic field-effect transistors (OFETs) are assembled in bottom gate-top contact architecture. A binary solvent system comprising of chloroform/toluene in the ratio of 1/1 is preferred for the deposition of active semiconducting layer. The fabricated devices demonstrated excellent p-type characteristics with a good mobility, high ON/OFF ratio of 10 9 and a minimum threshold voltage of À 4.5 V. Computational investigations indicted proper charge separation of the energy levels for the phenanthro[9,10-d] imidazole containing nitro group. Frontier molecular orbitals and the packing patterns obtained from computational studies suggest an efficient band gap for better device operation. The ordered morphologies of the molecules obtained from SEM analysis prove to be beneficial in the OFET performance. The photophysical, electrochemical and thermal properties of the molecules are studied in detail. The research work majorly emphasized on structural designing of the phenanthro[9,10-d]imidazoles for potential applications in organic devices.

Picene and PTCDI based solution processable ambipolar OFETs

“…The top contact ensures the uniform orientation of the active layer over dielectric layer where in the bottom contact devices, the orientation over electrodes and dielectric layer varies and thus disturbs the charge carrier movement. Therefore, minimum contact resistance is obtained in BGTC architecture 52 . The fabricated devices were characterized in ambient conditions; threshold voltage (V TH ) and charge carrier mobility (µ) were obtained from the intercept and slope of the linear plot of the square root of drain to source current (I DS 1/2 ) versus the gate voltage.…”

Aggregation Behavior and High Charge-Carrier OFET-Mobility of Functionalized Phenanthro[9,10-d]imidazoles

“…Tonzola et al and Kuo et al employed oligoquinoline and imidazole, respectively, for electron-transport properties to improve the efficiency of the device. − Moreover, it is also observed that in a molecular framework, PI as an electron-deficient unit significantly enhances electron injection and transport ability. , Our recent work demonstrated that structural tailoring of PI resulted in good OFET behavior . Based on these considerations, we functionalized PI with the incorporation of electron-donating and -accepting groups to facilitate the balance of charge carriers and hence enhance the device performance.…”

“…29,30 Our recent work demonstrated that structural tailoring of PI resulted in good OFET behavior. 35 Based on these considerations, we functionalized PI with the incorporation of electron-donating and -accepting groups to facilitate the balance of charge carriers and hence enhance the device performance.…”

Phenanthroimidazole-based Covalent Organic Frameworks with Enhanced Activity for the Photocatalytic Hydrogen Evolution Reaction

“…Phenanthroimidazole derivatives exhibit a rigid-planar-conjugate structure and ambipolar characteristics owing to the bonding structures of the two nitrogen atoms of the imidazole ring. 17,18 These derivatives have been widely employed as blue light-emitting materials based on their high carrier mobilities and conductivities, high triplet energies, and high fluorescent efficiencies. [19][20][21] Therefore, the phenanthroimidazole unit is a good candidate for the fabrication of COFs.…”