Magnetic‐Field‐Switchable Laser via Optical Pumping of Rubrene

Abstract

crystalline materials, garnets, or rare earth-doped paramagnetic glasses and are thus poorly suited to large-area and volumetric imaging. [4] Nitrogen vacancy (NV) centers provide high sensitivity to magnetic fields (on the order of 1 nT Hz −1/2 for a single NV center), [5] but NVs suffer from weak optical cross section, a requirement for high resolution detection of their emission wavelength, and difficult calibration. [6] Magnetic imaging applications would benefit from stronger optomagnetic interactions within biocompatible materials such as molecules or nanoparticles, which could be directly incorporated within a sample or bioassay. [7] Nanomaterials for magnetic imaging are ideally also capable of high-resolution imaging and operation at high photon flux, potentially even in microlasers, where brilliant emission and high spectral sensitivity creates new opportunities to monitor a wide range of physiological parameters with cellular resolution. [8] New optomagnetic effects in fluorescent or electroluminescent materials could be used to modulate lasers and may even find new applications in optical modulators, which presently rely on weak thermal or electro-optic effects.One alternative to conventional magneto-optical materials is suggested by proposed explanations for the sensitivity of birds to Earth's magnetic field. Recent studies suggest that birds are able to orient themselves to Earth's magnetic field by exploiting the magnetic sensitivity of electronic interactions in their retinas. [9,10] Photoexcitation of proteins in avian retinas produce radical (unpaired electron) intermediate states, which then interact with spin-1 excitons (electron-hole pairs), also known as triplet excitons. To understand the basis for the magnetic dependence of these interactions, consider an asymmetric molecule, for which the three triplet states of the spin-1 exciton are energetically split even in the absence of a magnetic field. Typically, without substantial spin-orbit coupling, this zero-field splitting is less than about 10 μeV. [11] Therefore, an external magnetic field on the order of 10 μeV μ B −1 (≈0.2 T), where μ B is the Bohr magneton, can reorder the triplet states via the Zeeman effect, modulating their involvement in spindependent interactions. The magnetic field sensitivity is typically even higher for an unpaired electron with no zero-field splitting. Consequently, both triplet-triplet and triplet-charge interactions can undergo magnetic field modulation. Given its Volumetric optical imaging of magnetic fields is challenging with existing magneto-optical materials, motivating the search for dyes with strong magnetic field interactions, distinct emission spectra, and an ability to withstand high photon flux and incorporation within samples. Here, the magnetic field effect on singlet-exciton fission is exploited to demonstrate spatial imaging of magnetic fields in a thin film of rubrene. Doping rubrene with the highquantum yield dye dibenzotetraphenylperiflanthene (DBP) is shown to enable optically pumped, slab...

Giant magneto-photoluminescence at ultralow field in organic microcrystal arrays for on-chip optical magnetometer

“…Magneto-optical phenomenon, typically the Faraday/Kerr rotation of transmitted/reflected light polarization under an external magnetic field, has been discovered and extensively studied since 1840s 1 , 2 . After that, a series of magneto-optical effects, such as magnetic circular dichroism and magneto-chiral dichroism, have been found 3 – 9 and used for light modulation with magnetic field 10 – 14 and/or optical magnetometry 15 – 18 . A distinct type of magneto-optical effects concerning the excited state in organic materials, such as magneto-photoluminescence (MPL) 19 – 31 and magneto-electroluminescence 30 – 37 , has attracted considerable attention in past decades.…”

Microstructure-driven annihilation effects and dispersive excited state dynamics in solid-state films of a model sensitizer for photon energy up-conversion applications

“…Next generation photon management strategies that can boost the performance of optoelectronic and photonic devices continue to surge in tandem with recent progress in the understanding of organic semiconductor spin-physics. [1][2][3][4] Smart wavelength-shiing techniques could be potentially applied through triplet-triplet annihilation induced photon energy up conversion (TTA-UC), a photophysical process that facilitates a low-to-high photon energy conversion under low photoexcitation intensities. From early on (ref.…”

“…[14][15][16] The solution processable character of TTA-UC organic materials offers an attractive opportunity to complement the portfolio of other existing photon energy up-converting systems [17][18][19][20][21] and to avoid disruptions in the design of currently employed device architectures. Although the realization of TTA-UC layers as functional device components is lagging, encouraging results were recently presented on a green-to-blue model TTA-UC composite prepared by blending the greenabsorbing (2,3,7,8,12,13,17,18-octaethyl-porphyrinato) Pt II (PtOEP) square-planar sensitizer with the blue-light emitting 9,10 diphenyl anthracene (DPA) emitter, a polycyclic aromatic hydrocarbon derivative. In particular, a striking TTA-UC PL quantum yield (PLQY UC ) of 8% (out of maximum 50%) was reported for optimized large-area DPA:PtOEP lms 22 that can be further improved with the aid of ceramic-based nanocomposite frameworks.…”

Magnetic properties and thermal behavior of the monolayer Rubrene-like nano-island: Monte Carlo simulations

“…On the other hand, Al-muntaser et al [20] have studied the role of the Rubrene semiconductor additive for reinforcing the optical and structural properties of the polyvinyl alcohol lms (PVA) towards optoelectronic applications. Moreover, Collin et al [21] have investigated the magnetic eld effect on singlet-exciton ssion to demonstrate spatial imaging of magnetic elds in a thin lm of Rubrene. Besides, the magnetic properties of different structures have recently been studied using Monte Carlo simulations (MCs) such as borophene nanoribbons with core-shell [22], Graphene-Like Nanoribbon [23], a checkerboard square [24] on honeycomb [25] and Tri-layer Graphyne-Like Structure [26].…”