N-Heteroacenes as an Organic Gain Medium for Room-Temperature Masers

Max Attwood; Xiaotian Xu; Michael Newns; Zhu Meng; Rebecca A Ingle; Hao Wu; Xi Chen; Weidong Xu; Wern Ng; Temitope T Abiola; Vasilios G Stavros; Mark Oxborrow

doi:10.1021/acs.chemmater.3c00640

N-Heteroacenes as an Organic Gain Medium for Room-Temperature Masers

Chem Mater. 2023 May 23;35(11):4498-4509. doi: 10.1021/acs.chemmater.3c00640. eCollection 2023 Jun 13.

Authors

Max Attwood¹, Xiaotian Xu¹, Michael Newns¹, Zhu Meng², Rebecca A Ingle³, Hao Wu⁴, Xi Chen^{1

5}, Weidong Xu², Wern Ng¹, Temitope T Abiola⁶, Vasilios G Stavros⁷, Mark Oxborrow¹

Affiliations

¹ Department of Materials, Imperial College London, South Kensington Campus, Exhibition Road, London SW7 2AZ, U.K.
² Molecular Sciences Research Hub, Department of Chemistry, Imperial College London, White City Campus, 82 Wood Lane, London W12 0BZ, U.K.
³ Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
⁴ Center for Quantum Technology Research and Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements, School of Physics, Beijing Institute of Technology, Beijing 100081, China.
⁵ Department of Computer Science, University of Southern California, Los Angeles, California 90089, United States.
⁶ Department of Chemistry, University of Toronto, 80 St. George Street, Toronto M5S 3H6, Canada.
⁷ Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.

Abstract

The development of future quantum devices such as the maser, i.e., the microwave analog of the laser, could be well-served by the exploration of chemically tunable organic materials. Current iterations of room-temperature organic solid-state masers are composed of an inert host material that is doped with a spin-active molecule. In this work, we systematically modulated the structure of three nitrogen-substituted tetracene derivatives to augment their photoexcited spin dynamics and then evaluated their potential as novel maser gain media by optical, computational, and electronic paramagnetic resonance (EPR) spectroscopy. To facilitate these investigations, we adopted an organic glass former, 1,3,5-tri(1-naphthyl)benzene to act as a universal host. These chemical modifications impacted the rates of intersystem crossing, triplet spin polarization, triplet decay, and spin-lattice relaxation, leading to significant consequences on the conditions required to surpass the maser threshold.