Photosensitivity and charge injection dynamics of pentacene based thin-film transistors: influence of substrate temperature
| Autor: | Anasua Khan, D. Panigrahi, Salma Khatun, Swastika Chatterjee, Amlan J. Pal, Aditi Sahoo, Achintya Dhar |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Electron mobility
Materials science 02 engineering and technology Substrate (electronics) 010402 general chemistry 01 natural sciences Biomaterials Pentacene chemistry.chemical_compound Materials Chemistry Electrical and Electronic Engineering Organic field-effect transistor business.industry Contact resistance Fermi energy General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Electronic Optical and Magnetic Materials Active layer chemistry Thin-film transistor Optoelectronics 0210 nano-technology business |
| Zdroj: | Organic Electronics. 70:172-178 |
| ISSN: | 1566-1199 |
| DOI: | 10.1016/j.orgel.2019.04.022 |
| Popis: | In this work, we have performed an in-depth analysis to investigate the effect of substrate temperature on the molecular packing arrangement and energy levels of pentacene films. We have also explored their influence on the charge injection mechanism and photosensing behaviour of pentacene-based organic field-effect transistors (OFETs). In this study, we find the contact resistance and photosensitivity of the devices to be severely influenced by the active layer processing condition owing to the aforementioned structural and energy level modifications. Contact resistance of the devices at metal-semiconductor interfaces was observed to be reduced significantly upon increase in the substrate temperature; however, above a certain temperature, formation of pentacene thin-films was severely affected and no transistor characteristics were obtained afterwards. Detailed experimental analysis and theoretical investigations revealed that the processing temperature could strongly influence the grain structure and unit cell volume of the pentacene molecules, which consequently enhanced the carrier injection across the interface through a control over carrier mobility and the distribution of electronic states in the proximity of Fermi energy. Furthermore, our study demonstrates the role of substrate temperature in effectively enhancing the photosensitivity of the transistors. This report thus represents a step forward towards understanding a correlation between the processing temperature and the dynamics of charge injection in pentacene based organic transistors. The results also illustrate the viability of using proper substrate temperature to achieve an efficient photosensitivity from OFET devices. |
| Databáze: | OpenAIRE |
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