Abstract
The development of high performance optically pumped organic lasers operating in the deep blue still remains a big challenge. In this paper, we have investigated the photophysics and the optical gain characteristics of a novel fluorene oligomer functionalized by four triphenylamine (TPA) groups. By ultrafast spectroscopy we found a large gain spectral region from 420 to 500 nm with a maximum gain cross-section of 1.5 × 10−16 cm2 which makes this molecule a good candidate for photonic applications. Amplified Spontaneous Emission measurements (ASE) under 150 fs and 3 ns pump pulses have revealed a narrow emission at 450 nm with a threshold of 5.5 μJcm−2 and 21 μJcm−2 respectively. Our results evidence that this new fluorene molecule is an interesting material for photonic applications, indeed the inclusion of TPA as a lateral substituent leads to a high gain and consequently to a low threshold blue organic ASE.
Highlights
Due to their good optical properties and low-cost large-area processing, organic π-conjugated semiconductors have gained much interest in different kinds of applications such as organic field-effect transistors (OFETs) [1,2,3] light-emitting diodes (OLEDs) [4,5], solar cells (OPVs) [6,7] and semiconductor lasers [8,9,10,11]
We have explored the photophysics of a F4TPA thin film by ultrafast spectroscopy and its gain properties by studying the Amplified Spontaneous Emission (ASE) both under impulsive and quasi steady state (QSS) pumping
The PL spectrum results to be stable in air with no appearance of the typical green large emission mainly due to the keto defect
Summary
Due to their good optical properties and low-cost large-area processing, organic π-conjugated semiconductors have gained much interest in different kinds of applications such as organic field-effect transistors (OFETs) [1,2,3] light-emitting diodes (OLEDs) [4,5], solar cells (OPVs) [6,7] and semiconductor lasers [8,9,10,11]. The great challenge of developing novel molecules with highly luminescent efficiencies, efficient optical gain, high photostability and low lasing thresholds in order to achieve electrically pumped organic lasers remains open [12]. To close this gap between the actual state of the art and the performances required for real applications, research on the development of novel materials for organic lasers is still ongoing.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
