Analysis of the persistent photoresponse of C8BTBT transistors in the near-bandgap spectral region
| Autor: | Fausta Loffredo, Antonio Facchetti, Riccardo Miscioscia, Mario Petrosino, Giuseppe Nenna, Carla Minarini, Fulvia Villani, Alfredo Rubino, Mitchell Denti |
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| Přispěvatelé: | Minarini, C., Villani, F., Nenna, G., Loffredo, F., Miscioscia, R. |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Materials Chemistry2506 Metals and Alloys
Materials science Band gap 02 engineering and technology OTFT 01 natural sciences Molecular physics law.invention Biomaterials law 0103 physical sciences Materials Chemistry Electronic Persistent photoresponse Irradiation Optical and Magnetic Materials Electrical and Electronic Engineering Exposure dose C8BTBT 010302 applied physics business.industry Transistor Chemistry (all) General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Electronic Optical and Magnetic Materials Threshold voltage Organic semiconductor Photoexcitation Semiconductor Optoelectronics Relaxation (physics) 0210 nano-technology business |
| Popis: | The variations in physical parameters of an organic field-effect transistor having dioctylbenzothieno[2,3-b]benzothiophene (C8BTBT) as the channel semiconductor were investigated under different light irradiation conditions at wavelengths of 350 nm, 370 nm, 400 nm and by increasing exposure doses. The progress of the electro-optical history of the transistor was evaluated by repeating I–V scan cycles both in the dark and under light exposure. The information recorded upon different exposure times was used to detect the photoactivated charge-trapping effects. The device showed a stable I–V response in the dark bias ( V DS = −10 V, −10 V ≤ V GS ≤ +10 V) conditions and a persistent threshold voltage ( V T ) shift under illumination at all irradiation wavelengths. We suggested that the observed dose-dependent V T drifts were due to charge retention in trap sites within the organic semiconductor. The threshold voltage was recognized as the main parameter affected by charge retention. V T variations were modelled versus time through a single exponential revealing a maximum in charge relaxation times for irradiations at wavelengths of 370 nm, in proximity of the C8BTBT bandgap energy. Furthermore, bias-stress effects and persistent photoinduced V T drifts were found to depend on comparable characteristic times. Therefore, a common nature for both the bias-stress decay and relaxation from photoexcitation mechanisms is likely. |
| Databáze: | OpenAIRE |
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