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

Raj Pandya (1) , Richard y S Chen (1) , Qifei Gu (1) , Jooyoung Sung (1) , Christoph Schnedermann (1) , Oluwafemi S Ojambati (1) , Rohit Chikkaraddy (1) , Jeffrey Gorman (1) , Gianni Jacucci (2) , Olimpia D Onelli (2) , Tom Willhammar (3) , Duncan N Johnstone (4) , Sean M Collins (4) , Paul A Midgley (4) , Florian Auras (1) , Tomi Baikie (1) , Rahul Jayaprakash (5) , Fabrice Mathevet (6) , Richard Soucek (7) , Matthew Du (8) , Antonios M Alvertis (1) , Arjun Ashoka (1) , Silvia Vignolini (2) , David G Lidzey (5) , Jeremy J Baumberg (1) , Richard H Friend (1) , Thierry Barisien (7) , Laurent Legrand (9) , Alex W. Chin (9) , Joel Yuen-Zhou (8) , Semion K Saikin (10) , Philipp Kukura (11) , Andrew J Musser (12, 13) , Akshay Rao (1)

1 Cavendish Laboratory
2 Department of Chemistry [Cambridge, UK]
3 Stockholm University
4 DMSM - Department of Materials Science and Metallurgy [Cambridge University]
5 Department of Physics and Astronomy [Sheffield]
6 IPCM - Institut Parisien de Chimie Moléculaire
7 INSP - Institut des Nanosciences de Paris
8 Chemistry SDSU - Department of Chemistry and Biochemistry [San Diego State Univ]
9 INSP-E12 - Photonique et cohérence de spin
10 Department of Chemistry and Chemical Biology [Harvard]
11 Physical and Theoretical Chemistry Laboratory [Oxford]
12 Department of Chemistry and Chemical Biology, Cornell University
13 Cornell University [New York]

Abstract Strong-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 × 10 6 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

Domaines: Matière Molle [cond-mat.soft]; Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]; Arithmétique des ordinateurs; Modélisation et simulation; Traitement du signal et de l'image [eess.SP]; Science des matériaux [cond-mat.mtrl-sci]; Physique Quantique [quant-ph]; Biophysique [physics.bio-ph]; Chimie-Physique [physics.chem-ph]; Physique Numérique [physics.comp-ph]; Agrégats Moléculaires et Atomiques [physics.atm-clus]

Raj Pandya, Richard y S Chen, Qifei Gu, Jooyoung Sung, Christoph Schnedermann, et al.. Microcavity-like exciton-polaritons can be the primary photoexcitation in bare organic semiconductors. Nature Communications, 2021, 12 (1), ⟨10.1038/s41467-021-26617-w⟩. ⟨hal-03429501⟩