Search results for "light-matter coupling"
showing 4 items of 4 documents
Controlling Exciton Propagation in Organic Crystals through Strong Coupling to Plasmonic Nanoparticle Arrays.
2022
Exciton transport in most organic materials is based on an incoherent hopping process between neighboring molecules. This process is very slow, setting a limit to the performance of organic optoelectronic devices. In this Article, we overcome the incoherent exciton transport by strongly coupling localized singlet excitations in a tetracene crystal to confined light modes in an array of plasmonic nanoparticles. We image the transport of the resulting exciton–polaritons in Fourier space at various distances from the excitation to directly probe their propagation length as a function of the exciton to photon fraction. Exciton–polaritons with an exciton fraction of 50% show a propagation length…
Vacuum-Deposited Microcavity Perovskite Photovoltaic Devices
2021
The interaction between semiconductor materials and electromagnetic fields resonating in microcavities or the light-matter coupling is of both fundamental and practical significance for improving the performance of various photonic technologies. The demonstration of light-matter coupling effects in the emerging perovskite-based optoelectronic devices via optical pumping and electrical readout (e.g., photovoltaics) and vice versa (e.g., light-emitting diodes), however, is still scarce. Here, we demonstrate the microcavity formation in vacuum-deposited methylammonium lead iodide (CH3NH3PbI3, MAPI) p-i-n photovoltaic devices fabricated between two reflecting silver electrodes. We tune the posi…
Light-Driven Extremely Nonlinear Bulk Photogalvanic Currents
2021
We predict the generation of bulk photocurrents in materials driven by bichromatic fields that arc circularly polarized and corotating. The nonlinear photocurrents have a fully controllable directionality and amplitude without requiring carrier-envelope-phase stabilization or few-cycle pulses, and can be generated with photon energies much smaller than the band gap (reducing heating in the photoconversion process). We demonstrate with ab initio calculations that the photocurrent generation mechanism is universal and arises in gaped materials (Si, diamond, MgO, hBN), in semimetals (graphene), and in two- and three-dimensional systems. Photocurrents are shown to rely on sub-laser-cycle asymme…
Multiscale Molecular Dynamics Simulations of Polaritonic Chemistry.
2017
When photoactive molecules interact strongly with confined light modes as found in plasmonic structures or optical cavities, new hybrid light-matter states can form, the so-called polaritons. These polaritons are coherent superpositions (in the quantum mechanical sense) of excitations of the molecules and of the cavity photon or surface plasmon. Recent experimental and theoretical works suggest that access to these polaritons in cavities could provide a totally new and attractive paradigm for controlling chemical reactions that falls in between traditional chemical catalysis and coherent laser control. However, designing cavity parameters to control chemistry requires a theoretical model wi…