TY  - JOUR
A1  - Koopman, Wouter-Willem Adriaan
A1  - Natali, Marco
A1  - Donati, Giovanni P.
A1  - Muccini, Michele
A1  - Toffanin, Stefano
T1  - Charge-exciton interaction rate in organic field-effect transistors by means of transient photoluminescence electromodulated spectroscopy
JF  - ACS photonics
N2  - 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.
KW  - photoluminescence quenching
KW  - charge density
KW  - exciton dynamics
KW  - organic
KW  - field-effect transistor
KW  - light emission
KW  - optical spectroscopy
Y1  - 2017
U6  - https://doi.org/10.1021/acsphotonics.6b00573
SN  - 2330-4022
VL  - 4
IS  - 2
SP  - 282
EP  - 291
PB  - American Chemical Society
CY  - Washington, DC
ER  -