scholarly journals Microcavity-like exciton-polaritons can be the primary photoexcitation in bare organic semiconductors

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Raj Pandya ◽  
Richard Y. S. Chen ◽  
Qifei Gu ◽  
Jooyoung Sung ◽  
Christoph Schnedermann ◽  
...  
Keyword(s):  
Strong Coupling ◽  
Organic Semiconductors ◽  
Free Exciton ◽  
External Cavity ◽  
Einstein Condensation ◽  
Strong Light ◽  
Exciton Polaritons ◽  
Organic Optoelectronic ◽  
Bose Einstein ◽  
New Generation

AbstractStrong-coupling between excitons and confined photonic modes can lead to the formation of new quasi-particles termed exciton-polaritons which can display a range of interesting properties such as super-fluidity, ultrafast transport and Bose-Einstein condensation. Strong-coupling typically occurs when an excitonic material is confided in a dielectric or plasmonic microcavity. Here, we show polaritons can form at room temperature in a range of chemically diverse, organic semiconductor thin films, despite the absence of an external cavity. We find evidence of strong light-matter coupling via angle-dependent peak splittings in the reflectivity spectra of the materials and emission from collective polariton states. We additionally show exciton-polaritons are the primary photoexcitation in these organic materials by directly imaging their ultrafast (5 × 106 m s−1), ultralong (~270 nm) transport. These results open-up new fundamental physics and could enable a new generation of organic optoelectronic and light harvesting devices based on cavity-free exciton-polaritons

Strong Coupling: Polariton Bose Condensation

2017 ◽  
Author(s):  
Alexey V. Kavokin ◽  
Jeremy J. Baumberg ◽  
Guillaume Malpuech ◽  
Fabrice P. Laussy
Keyword(s):  
Strong Coupling ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Dissipative System ◽  
Bose Condensation ◽  
Einstein Condensation ◽  
Strong Coupling Regime ◽  
Stimulated Scattering ◽  
Exciton Polaritons ◽  
Bose Einstein

In this Chapter we address the physics of Bose-Einstein condensation and its implications to a driven-dissipative system such as the polariton laser. We discuss the dynamics of exciton-polaritons non-resonantly pumped within a microcavity in the strong coupling regime. It is shown how the stimulated scattering of exciton-polaritons leads to formation of bosonic condensates that may be stable at elevated temperatures, including room temperature.

scholarly journals Microcavity-Like Exciton-Polaritons can be the Primary Photoexcitation in Bare Organic Semiconductors

2021 ◽  
Author(s):  
Akshay Rao ◽  
Raj Pandya ◽  
Richard Chen ◽  
Qifei Gu ◽  
Jooyoug Sung ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Room Temperature ◽  
External Cavity ◽  
Materials Chemistry ◽  
Strong Light ◽  
Organic Systems ◽  
Reflectivity Spectra ◽  
Wide Range ◽  
Exciton Polaritons ◽  
Photonic States

Abstract Exciton-polaritons (EPs) are quasiparticles formed by the hybridization of excitons with light modes. As organic semiconductors sustain stable excitons at room-temperature, these materials are being actively studied for room temperature polaritonic devices1–3. This is typically in the form of cavity-based systems, where molecules are confined between metallic or dielectric mirrors 4–6 or in a plasmonic gap 7,8. In such systems strong light-matter coupling gives rise to polariton splittings on the order of 200 to 300 meV 6. A wide range of phenomena have been demonstrated in cavity-polariton systems including super-fluidity9, precisely controlled chemical reactions10 and long-range energy propagation11. Here, using a range of chemically diverse model organic systems we show that interactions between excitons and moderately confined photonic states within the (thin) film can lead to the formation of EPs, with a defined lifetime, even in the absence of external cavities. We demonstrate the presence of EPs via angular dependent splittings in reflectivity spectra on the order of 30 meV and collective emission from ~5 ×107 coupled molecules. Additionally, we show that at room temperature these EPs can transport energy up to ~270 nm at velocities of ~5 ×106 m s-1. This propagation velocity and distance is sensitive to, and can be tuned by, the refractive index of the external environment. However, although sensitive to the nanoscale morphology the formation of the exciton-polariton states is a general phenomenon, independent of underlying materials chemistry, with the principal material requirements being a high oscillator strength per unit volume and low disorder. These results and design rules will enable the harnessing of EP effects for a new application in optoelectronics, light harvesting 9,12,13 and cavity controlled chemistry without the limiting requirement of an external cavity.

scholarly journals Strong light-matter coupling in dielectric metasurfaces

2020 ◽  
Vol 238 ◽  
pp. 05004
Author(s):  
Gabriel W. Castellanos ◽  
Shunsuke Murai ◽  
T.V. Raziman ◽  
Shaojun Wang ◽  
Mohammad Ramezani ◽  
...  
Keyword(s):  
Strong Coupling ◽  
Silicon Nanoparticles ◽  
Organic Molecules ◽  
Quality Factors ◽  
Low Loss ◽  
Strong Light ◽  
Large Coupling ◽  
Exciton Polaritons ◽  
Coupling Strengths ◽  
Individual Nanoparticles

We demonstrate the strong coupling between excitons in organic molecules and all-dielectric metasurfaces formed by arrays of silicon nanoparticles supporting Mie surface lattice resonances (MSLRs). Compared to Mie resonances in individual nanoparticles, MSLRs have extended mode volumes and much larger quality factors, which enables to achieve collective strong coupling with very large coupling strengths and Rabi energies. Moreover, due to the electric and magnetic character of the MSLR given by the Mie resonance, we show that the hybridization of the exciton with the MSLR results in exciton-polaritons that inherit this character as well. Our results demonstrate the potential of all-dielectric metasurfaces as novel platform to investigate and manipulate exciton-polaritons in low-loss polaritonic devices.

Bose–Einstein Condensation of Exciton-Polaritons in Organic Microcavities

2020 ◽  
Vol 71 (1) ◽  
pp. 435-459 ◽  
Author(s):  
Jonathan Keeling ◽  
Stéphane Kéna-Cohen
Keyword(s):  
Room Temperature ◽  
Organic Molecules ◽  
Einstein Condensation ◽  
Electronic Excitations ◽  
Optical Mode ◽  
Optical Cavities ◽  
Bose Einstein Condensation ◽  
Exciton Polaritons ◽  
Basic Physics ◽  
Bose Einstein

Bose–Einstein condensation describes the macroscopic occupation of a single-particle mode: the condensate. This state can in principle be realized for any particles obeying Bose–Einstein statistics; this includes hybrid light-matter excitations known as polaritons. Some of the unique optoelectronic properties of organic molecules make them especially well suited for the realization of polariton condensates. Exciton-polaritons form in optical cavities when electronic excitations couple collectively to the optical mode supported by the cavity. These polaritons obey bosonic statistics at moderate densities, are stable at room temperature, and have been observed to form a condensed or lasing state. Understanding the optimal conditions for polariton condensation requires careful modeling of the complex photophysics of organic molecules. In this article, we introduce the basic physics of exciton-polaritons and condensation and review experiments demonstrating polariton condensation in molecular materials.

Cavity Exciton-Polaritons, Bose Einstein Condensation and Spin Dynamics

2009 ◽  
Author(s):  
Guillaume Malpuech ◽  
Dmitry Solnyshkov ◽  
Ivan Shelykh ◽  
Dmitry N. Chigrin
Keyword(s):  
Spin Dynamics ◽  
Einstein Condensation ◽  
Bose Einstein Condensation ◽  
Exciton Polaritons ◽  
Bose Einstein

Robust Polariton Bose–Einstein Condensation Laser via a Strong Coupling Microcavity

2020 ◽  
Vol 14 (12) ◽  
pp. 2000273
Author(s):  
Zhiyang Chen ◽  
Huying Zheng ◽  
Hai Zhu ◽  
Ziying Tang ◽  
Yaqi Wang ◽  
...  
Keyword(s):  
Strong Coupling ◽  
Einstein Condensation ◽  
Bose Einstein Condensation ◽  
Bose Einstein
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