Tuning dielectric-semiconductor interfacial properties in organic phototransistors for ultralow light detection
| Autor: | Achintya Dhar, D. Panigrahi |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Gate dielectric 02 engineering and technology Dielectric 010402 general chemistry 01 natural sciences law.invention Biomaterials Responsivity Photosensitivity law Materials Chemistry Electrical and Electronic Engineering chemistry.chemical_classification business.industry General Chemistry Polymer equipment and supplies 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Electronic Optical and Magnetic Materials Photodiode Semiconductor chemistry Optoelectronics Field-effect transistor 0210 nano-technology business |
| Zdroj: | Organic Electronics. 70:107-112 |
| ISSN: | 1566-1199 |
| DOI: | 10.1016/j.orgel.2019.04.009 |
| Popis: | The quality of the dielectric-semiconductor interface plays a very crucial role in determining the photosensory performances of the organic field effect transistors. Herein, we have investigated the influence of polymer molecular weight on the photosensing behaviour of the organic transistors. In this study, we find high molecular weight PMMA to be more effective as gate dielectric in phototransistor applications compared to the low molecular weight PMMA due to the better morphological arrangements of the active semiconducting layer on top of its surface. The maximum values of photosensitivity and responsivity improved substantially from 3.5 × 104 and 8.3 × 103 A/W in the low molecular weight PMMA devices to 105 and 6.9 × 104 A/W in the high molecular weight PMMA devices, respectively, under same intensity light irradiation. Moreover, we have also proposed a simple, yet highly efficient interface modification technique to enhance the photosensitivity of the transistors under low light illumination through the plasma treatment of the dielectric layer. After the interface modification of the high molecular weight PMMA devices, the photosensitivity value enhanced significantly from 3.67 × 102 to 7.08 × 103 under an ultralow optical power of 5 μW/cm2. Post interface modification improvements in the device photosensitivity values were attributed to the plasma induced generation of polar surface functionalities which effectively enhance the number of free holes in the channel region by trapping the photo-generated electrons at the interface. This report, thus, represents a step forward towards improving the performance of the phototransistors for their applications in high performance organic optoelectronic devices. |
| Databáze: | OpenAIRE |
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