Tunable Emission from Localized Excitons Deterministically Positioned in Monolayer p–n Junctions

Abstract

Transition metal dichalcogenides (TMDs) are a promising solid-state platform for single photon emission. The versatile fabrication methods afforded by their two-dimensional nature facilitate the integration of TMDs into optoelectronic devices where localized exciton states can be electrically pumped. While this functionality is highly desirable for applications in quantum nanophotonics, enabling more compact and scalable devices, the lack of control of emitter spatial positions and energies has impeded the integration of TMDs into quantum optical systems. Here we demonstrate single photon electroluminescence from monolayer WSe 2 in a lateral gate-defined junction that allows the electrostatic environment to be tuned in situ. By utilizing local strain engineering, we reliably position bright localized exciton states in the optically active region of the gate-defined junction, enabling the deterministic creation of devices that predominantly produce single photon emission. Modulation of the gate voltages tunes the emission between different electrostatic regimes, revealing a new localized exciton state that exhibits a gate-dependent redshift. A spectral shift of the electroluminescence of over 10 meV is achieved, demonstrating the capability for simultaneous electrical pumping and tuning of localized exciton emission in TMD devices.

One (photon), two(-dimensional crystals), a lot (of potential): a quick snapshot of a rapidly evolving field

“…More in general, electrical manipulation of TMDC SPEs also led to phenomena such as Coulomb blockade, i.e. the loading of single electrons or holes, one by one, into a QE [100]; to the creation of localised trions, featuring a reduced FSS when compared to the neutral exciton species [101]; or to the simultaneous electrical pumping and energy tuning of SPEs via a lateral p-n junction, interfaced with a WSe 2 ML placed on top of a dielectric nanopillar [102]. Moreover, a hybrid electro-optical approach has been recently demonstrated by the appearance of QEs in a WSe 2 ML deposited on a substrate comprised of GaN-based µ-LEDs, operating at low temperatures [103].…”

Mn(II)-Activated Zero-Dimensional Zinc(II)-Based Metal Halide Hybrids with Near-Unity Photoluminescence Quantum Yield

“…Each [MnBr 4 ] 2− tetrahedron is separated by organic cations to form the highly localized electrons in Mn 2+ :(TDMP)ZnBr 4 , thus generating the isolated luminescent centers. This highly localized electron is a key factor in producing efficient luminescence [22,61].…”

“…Materials 2024, 17, x FOR PEER REVIEW 9 of 13 thus generating the isolated luminescent centers. This highly localized electron is a key factor in producing efficient luminescence [22,61].…”

Alice (and Bob) in Flatland

“…49 Simultaneous electrical pumping and energy tuning of SPEs via a p−n junction, interfaced with a WSe 2 ML atop of a dielectric nanopillar (which also acts as a stressor), was also achieved. 73 Achieving electrical control of the emitters represents indeed an important step toward the integration of 2D-material-based SPEs in actual devices, and further studies in this direction might boost their use for QTs.…”