Excitonic lasing in solution-processed subwavelength nanosphere assemblies
Abstract
Lasing in solution-processed nanomaterials has gained significant interest because of the potential for low-cost integrated photonic devices. Still, a key challenge is to utilize a comprehensive knowledge of the system’s spectral and temporal dynamics to design low-threshold lasing devices. Here, we demonstrate intrinsic lasing (without external cavity) at low-threshold in an ultrathin film of coupled, highly crystalline nanospheres with overall thickness on the order of ~λ/4. The cavity-free geometry consists of ~35 nm zinc oxide nanospheres that collectively localize the in-plane emissive light fields while minimizing scattering losses, resulting in excitonic lasing with fluence thresholds at least an order of magnitude lower than previous UV-blue random and quantum-dot lasers (<75 μJ/cm2). Fluence-dependent effects, as quantified by subpicosecond transient spectroscopy, highlight the role of phonon-mediated processes in excitonic lasing. Subpicosecond evolution of distinct lasing modes, together with three-dimensional electromagnetic simulations, indicate a random lasing process, which is in violation of the commonly cited criteria of strong scattering from individual nanostructures and an optically thick sample. Subsequently, an electron–hole plasma mechanism is observed with increased fluence. Furthermore, these results suggest that coupled nanostructures with high crystallinity, fabricated by low-cost solution-processing methods, can function as viable building blocks for high-performance optoelectronics devices.
- Authors:
-
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- City College of New York, New York, NY (United States)
- Publication Date:
- Research Org.:
- Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials (CFN)
- Sponsoring Org.:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- OSTI Identifier:
- 1328365
- Report Number(s):
- BNL-112646-2016-JA
Journal ID: ISSN 1530-6984; R&D Project: 16063; 16058; KC0403020
- Grant/Contract Number:
- SC00112704
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Nano Letters
- Additional Journal Information:
- Journal Volume: 16; Journal Issue: 3; Journal ID: ISSN 1530-6984
- Publisher:
- American Chemical Society
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; cavity-free; electron-phonon coupling; near-field enhancement; room-temperature random lasing; solution-processed film; ultrafast dynamics; Center for Functional Nanomaterials
Citation Formats
Appavoo, Kannatassen, Liu, Xiaoze, Menon, Vinod, and Sfeir, Matthew Y. Excitonic lasing in solution-processed subwavelength nanosphere assemblies. United States: N. p., 2016.
Web. doi:10.1021/acs.nanolett.5b05274.
Appavoo, Kannatassen, Liu, Xiaoze, Menon, Vinod, & Sfeir, Matthew Y. Excitonic lasing in solution-processed subwavelength nanosphere assemblies. United States. https://doi.org/10.1021/acs.nanolett.5b05274
Appavoo, Kannatassen, Liu, Xiaoze, Menon, Vinod, and Sfeir, Matthew Y. Wed .
"Excitonic lasing in solution-processed subwavelength nanosphere assemblies". United States. https://doi.org/10.1021/acs.nanolett.5b05274. https://www.osti.gov/servlets/purl/1328365.
@article{osti_1328365,
title = {Excitonic lasing in solution-processed subwavelength nanosphere assemblies},
author = {Appavoo, Kannatassen and Liu, Xiaoze and Menon, Vinod and Sfeir, Matthew Y.},
abstractNote = {Lasing in solution-processed nanomaterials has gained significant interest because of the potential for low-cost integrated photonic devices. Still, a key challenge is to utilize a comprehensive knowledge of the system’s spectral and temporal dynamics to design low-threshold lasing devices. Here, we demonstrate intrinsic lasing (without external cavity) at low-threshold in an ultrathin film of coupled, highly crystalline nanospheres with overall thickness on the order of ~λ/4. The cavity-free geometry consists of ~35 nm zinc oxide nanospheres that collectively localize the in-plane emissive light fields while minimizing scattering losses, resulting in excitonic lasing with fluence thresholds at least an order of magnitude lower than previous UV-blue random and quantum-dot lasers (<75 μJ/cm2). Fluence-dependent effects, as quantified by subpicosecond transient spectroscopy, highlight the role of phonon-mediated processes in excitonic lasing. Subpicosecond evolution of distinct lasing modes, together with three-dimensional electromagnetic simulations, indicate a random lasing process, which is in violation of the commonly cited criteria of strong scattering from individual nanostructures and an optically thick sample. Subsequently, an electron–hole plasma mechanism is observed with increased fluence. Furthermore, these results suggest that coupled nanostructures with high crystallinity, fabricated by low-cost solution-processing methods, can function as viable building blocks for high-performance optoelectronics devices.},
doi = {10.1021/acs.nanolett.5b05274},
journal = {Nano Letters},
number = 3,
volume = 16,
place = {United States},
year = {Wed Feb 03 00:00:00 EST 2016},
month = {Wed Feb 03 00:00:00 EST 2016}
}
Web of Science