Abstract
Organic microlasers hold great potentials in fabricating on-chip sensors for integrated photonic circuits due to their chemical versatility and reactivity. However, chemical vapor detection is still challenging for organic microlaser sensors, as it requires not only optical gain and self-assembly capability, but also rapid response to stimuli and long-term stability under high excitation power. In this work, a new laser dye 4,7-bis(9-octyl-7-(4-(octyloxy)phenyl)-9H-carbazol-2-yl)benzo[c][1,2,5]thiadiazole (BPCBT) is designed and synthesized, which self-assembles into microwires showing strong intramolecular charge transfer (ICT) photoluminescence with >80% quantum efficiency. It enables the lasing from BPCBT microwires under a low threshold of 16 μJ·mm−2·pulse−1 with significantly improved stability over conventional organic microlasers. The stimulated emission amplifies the fluorescence change in the BPCBT microwires under chemical vapors including various acid, acetone, and ethanol vapors, indicating high sensitivity and high selectivity of organic microlaser sensors desirable for compact sensor arrays in integrated photonics.
Highlights
Organic microlasers hold great potentials in fabricating on-chip sensors for integrated photonic circuits due to their chemical versatility and reactivity
Besides high optical gain coefficient, organic dye molecules take advantages of chemical versatility as well as sensitivity to external stimuli compared with their inorganic counterpart[7,8,9], which extends their potential applications from microlasers to on-chip chemical sensors
In the BPCBT molecule, the benzothiadiazole unit is sandwiched between two carbazole groups resulting in a symmetrical D-A-D structure (Fig. 1a)
Summary
Organic microlasers hold great potentials in fabricating on-chip sensors for integrated photonic circuits due to their chemical versatility and reactivity. A new laser dye 4,7-bis(9-octyl-7-(4-(octyloxy)phenyl)9H-carbazol-2-yl)benzo[c][1,2,5]thiadiazole (BPCBT) is designed and synthesized, which self-assembles into microwires showing strong intramolecular charge transfer (ICT) photoluminescence with >80% quantum efficiency It enables the lasing from BPCBT microwires under a low threshold of 16 μJ·mm−2·pulse−1 with significantly improved stability over conventional organic microlasers. The competition between radiative and nonradiative excited-state processes in ICT molecules would lead to a leverage effect on the population distribution of photoexcitations and the enhancement of sensitivity via stimulated emission[26] This design strategy of ICT molecules offers a promising approach to microlaser-based chemical vapor sensors, as well as other functional on-chip units using organic microlasers in chemo/bioanalytical and environmental fields[27]. Of BPCBT. c TEM image of BPCBT microwires. d Corresponding SAED pattern. e Fluorescence microscopy images of large-area BPCBT microwires and a single microwire
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
