Bottom-gate Organic Thin Film Research Articles

Effect of temperature modulation on the performance of top contact bottom gate organic thin film transistor

This research article investigates the influence of temperature variations on the performance parameters of Top Contact Bottom Gate (TCBG) Organic Thin Film Transistors (OTFTs). Employing the Arrhenius equation and Schottky emission model, the study explores temperature-dependent charge carrier mobility and injection mechanisms. Analyzing a wide range of parameters, the research unveils a complex interplay between temperature and OTFT behavior. The linear and saturation mobilities exhibit a decline due to enhanced carrier-phonon interactions and lattice vibrations. Transconductance and ION/IOFF ratio display a concomitant decrease at higher temperatures, indicative of the heightened susceptibility of OTFT performance to temperature fluctuations. The depreciation in subthreshold slope and threshold voltage with rising temperatures underscores the influence of temperature on trap states. The research emphasizes the importance of considering temperature’s impact during OTFT design for diverse applications, enhancing the reliability and functionality of organic electronic devices.

Effect of source and drain electrode positions on the performance of bottom gate organic thin film transistor

In recent years several novel technologies have emerged on commercial level. Organic electronics is one such technology that has created new avenues for the development of flexible, robust, and cost-effective electronic devices. Transistor developed using organic materials are called organic thin film transistors (OTFT). Transistor is elementary component of any electronic device, any variation in the size or performance of the transistors reflects directly on the overall performance of the electronic devices. Bottom gate bottom contact (BGBC) OTFT is commonly employed single gate organic transistor owing to its simple architecture and easy fabrications. Since in organic semiconductor material carrier mobility of charges is lower, hence its overall performance declines. As a result, its application in electronic circuits becomes limited. Therefore, to enhance the performance of BGBC OTFT and facilitate the optimal charge mobilisation inside organic semiconductor layer i.e., OSC, improvement in the architecture of BGBC is deemed necessary. In this research article the performance of BGBC OTFT is analysed for different positions of electrodes viz. source and drain embedded inside the OSC layer. The study signifies the effect of electrode positions on performance optimization of BGBC OTFT without changing the materials, dimensions, or the operating voltage regime. It has been found that for 30 nm thick OSC layer, the electrodes should ideally be placed between 5 nm to 10 nm above the junction of OSC and dielectric layer inside OSC layer for optimal results.

Naphthalenediimides Fused with 2-(1,3-Dithiol-2-ylidene)acetonitrile: Strong Electron-Deficient Building Blocks for High-Performance n-Type Polymeric Semiconductors.

Naphthalenediimides (NDI) fused with two 2-(1,3-dithiol-2-ylidene)acetonitrile moieties (NDI-DTYA2), a novel strong electron-deficient monomer, was designed and readily synthesized by aromatic nucleophilic substitution to develop n-type polymers. Two NDI-DTYA2 based donor-acceptor (D-A) polymers P(NDI-DTYA2-1T) and P(NDI-DTYA2-2T) have been prepared (1T = thiophene, 2T = 2,2'-bithiophene) and showed low-lying LUMO energies (<-4.2 eV) and near-infrared optical absorptions (optical band gap <1.3 eV). Although the film feature of these polymers is amorphous, pure electron transport with high mobility of up to 0.38 cm2 V -1 s -1 could be achieved for their bottom gate organic thin film transistors, which was among the highest performances for unipolar n-type polymers. The results demonstrate that NDI-DTYA2 derivatives are promising building blocks for developing electron transport π-functional materials.

Characterization of 6,13-bis(triisopropylsilylethynyl) pentacene organic thin film transistors fabricated using pattern-induced confined structure

Bottom gate organic thin film transistors (OTFTs) were fabricated on polyethersulphone substrate using an ink jet printing method. 6,13-bis(triisopropylsilylethynyl) (TIPS) pentacene and poly-4-vinylphenol (PVP) were used as an active material and as a gate insulator, respectively. In an attempt to reduce the coffee stain effect, TIPS pentacene active layer was printed onto the pattern-induced confined structure (PICS) which had been obtained by orthogonally printing Ag electrodes on the pre-printed PVP layer. The resolution of Ag patterns was obtained by modifying the surface energy using UV irradiation and substrate temperature. The channel lengths of the aforementioned PICS OTFTs were in the range of 10μm to 50μm. The average mobility and on/off ratio of PICS OTFTs were 0.034cm2/Vs and 103, respectively.