Charge-exciton interaction rate in organic field-effect transistors by means of transient photoluminescence electromodulated spectroscopy
- Organic light-emitting transistors (OLETs) offer a huge potential for the design of highly integrated multifunctional optoelectronic systems and of intense nano scale light sources, such as the long-searched-for electrically pumped organic laser. In order to fulfill these promises, the efficiency and brightness of the current state-of-the-art devices have to be increased significantly. The dominating quenching process limiting the external quantum efficiency in OLETs is charge-exciton interaction. A comprehensive understanding of this quenching process is therefore of paramount importance. The present article reports a systematic investigation of charge-exciton interaction in organic transistors employing time resolved photoluminescence electro-modulation (PLEM) spectroscopy on the picosecond time scale. The results show that the injected charges reduce the exciton radiative recombination in two ways: (i) charges may prevent the generation of excitons and (ii) charges activate a further nonradiative channel for the exciton decay.Organic light-emitting transistors (OLETs) offer a huge potential for the design of highly integrated multifunctional optoelectronic systems and of intense nano scale light sources, such as the long-searched-for electrically pumped organic laser. In order to fulfill these promises, the efficiency and brightness of the current state-of-the-art devices have to be increased significantly. The dominating quenching process limiting the external quantum efficiency in OLETs is charge-exciton interaction. A comprehensive understanding of this quenching process is therefore of paramount importance. The present article reports a systematic investigation of charge-exciton interaction in organic transistors employing time resolved photoluminescence electro-modulation (PLEM) spectroscopy on the picosecond time scale. The results show that the injected charges reduce the exciton radiative recombination in two ways: (i) charges may prevent the generation of excitons and (ii) charges activate a further nonradiative channel for the exciton decay. Moreover, the transient PLEM measurements clearly reveal that not only trapped charges, as already reported in literature, but rather the entire injected charge density contributes to the quenching of the exciton population.…
Author details: | Wouter-Willem Adriaan KoopmanORCiDGND, Marco NataliORCiD, Giovanni P. Donati, Michele MucciniORCiD, Stefano ToffaninORCiD |
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DOI: | https://doi.org/10.1021/acsphotonics.6b00573 |
ISSN: | 2330-4022 |
Title of parent work (English): | ACS photonics |
Publisher: | American Chemical Society |
Place of publishing: | Washington, DC |
Publication type: | Article |
Language: | English |
Date of first publication: | 2017/01/19 |
Publication year: | 2017 |
Release date: | 2022/06/29 |
Tag: | charge density; exciton dynamics; field-effect transistor; light emission; optical spectroscopy; organic; photoluminescence quenching |
Volume: | 4 |
Issue: | 2 |
Number of pages: | 10 |
First page: | 282 |
Last Page: | 291 |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
Peer review: | Referiert |