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Anatoly P. Pushkarev

Publications and source records attributed to Anatoly P. Pushkarev.

6 recordsLinked to original sources

Colloidal Nanocrystals Regrowth-Assisted Synthesis of Perovskite Microwire Lasers for Integrated Optoelectronics

Colloidal perovskite nanocrystals (NCs) are a well-proven platform for growing anisotropic structures. Nanowires (NWs) exhibiting a quantum confinement phenomenon and microwires (MWs), which enable lasing, are of particular interest for optoelectronic devices. Synthesis of the latter is challenging. Herein, we report a straightforward access to high-quality CsPbBr3 MW lasers. We utilize a diphenyl ether (DPE) solvent for the hot-injection synthesis. DPE coordinates strongly to Pb2+ and allows to reduce an excess of oleic acid/oleylamine ligand pair well established for PbBr2 dissolution and inhibition of as-formed NCs regrowth. Therefore, a rapid injection of Cs-oleate into the PbBr2-containing solution yields lead-depleted Cs4PbBr6 NCs which slowly release perovskite precursors and produce CsPbBr3 counterparts. The latter transform into NWs through an oriented-attachment mechanism, which in turn evolve into laser MWs. To demonstrate spectrally tunable lasing in MWs we employ YCl3 for ion exchange in perovskite lattice. Resultant CsPb(Cl,Br)3 MWs show high-Q coherent emission in the 485-540 nm range. To highlight the potential of synthesized MWs for integrated optoelectronics, we assemble a device comprising a CsPb(Cl,Br)3 MW laser coupled to MoO3 lossless nanowaveguide, which delivers coherent light to a CsPbBr3 MW photodetector. The device exhibits a nonlinear optoelectronic response applicable for on-chip neuromorphic computing.

physics.optics

Model of luminescence and delayed luminescence correlated blinking in single CsPbBr$_3$ nanocrystals

Cesium lead halide nanocrystals and quantum dots are prominent materials for different types of applications because of their remarkable photophysical properties. However, they are also known to exhibit the same effects observed for non-perovskite colloidal semiconductor quantum dots such as blinking, photobleaching, delayed luminescence, etc. In this study we reveal the correlations between fast and delayed emission components for both the intensity and characteristic decay time for single CsPbBr$_3$ nanocrystals. In order to explain the phenomena observed, we propose a novel model of single CsPbBr$_3$ nanocrystals luminescence blinking based on the hypothesis of slow variations in the electron-phonon coupling.

cond-mat.mtrl-sci

Non-epitaxial perovskite polariton laser diode operating under direct current

Reaching lasing in electrically pumped microdevices based on solution-processed semiconductors poses a major scientific and technological challenge. Halide perovskites offer a promising platform for electrical injection, since their optically excited single-crystal cavities and predesigned or postprocessed microstructures have exhibited low lasing threshold. Indirect electrical pumping of a dual-cavity perovskite laser was recently obtained, utilizing a well-established technological concept of embedding a high-luminosity light-emitting diode (LED) with a high-gain medium into an integrated device. Direct charge-carrier injection into a perovskite LED excited by auxiliary short-, optical-pulses resulted into amplified spontaneous emission. Other efforts for rational engineering of architectures that allow for high charge-carrier density are still to demonstrate lasing. Here, we develop a novel strategy for achieving direct electrical pumping of a perovskite laser. We integrate a solution-grown CsPbBr3 microplate with chemically inert single-walled carbon nanotube electrodes and embed them into an optical microcavity. By cooling the microdevice down to 8 K at a constant current, a perovskite p-i-n diode is formed that facilitates a balanced carrier injection at high current densities. The perovskite microcavity diode operates in the strong coupling regime, exhibiting polariton lasing under a direct current of 65 uA.

physics.optics

Photoinduced transition from quasi-2D Ruddlesden-Popper to 3D halide perovskites for optical writing multicolor and light-erasable images

Development of advanced optical data storage, information encryption, and security labeling technologies requires low-cost materials exhibiting local, pronounced, and diverse modification of their structure-dependent optical properties under external excitation. Herein, for these purposes, we propose and develop a novel platform relying on layered lead halide Ruddlesden-Popper (quasi-2D) phases that undergo a light-induced transition towards bulk (3D) halide perovskite and employ this phenomenon for the direct optical writing of various multicolor patterns. This transition causes the weakening of quantum confinement, and hence the bandgap reduction in these photoluminescent thin films. To significantly extend the color gamut of evolving photoluminescence, we make use of mixed-halide compositions exhibiting photoinduced halide segregation. As a result, the emission wavelength of the resulting films can be widely tuned across the entire 450-600 nm range depending on the illumination conditions. We show that pulsed near-infrared femtosecond laser irradiation provides high-resolution direct writing, whereas continuous-wave ultraviolet exposure is suitable for fast recording on larger scales. The luminescent micro- and macro-scale images created on such quasi-2D perovskite films can be erased during the visualization process, by which the persistence of these images to UV light exposure can be controlled and increased further with the increasing number of octahedral layers used in the perovskite stacks. This makes the proposed writing/erasing perovskite-based platform suitable for the manufacturing of both inexpensive optical data storage devices and light-erasable security labels.

physics.optics

Light-controlled multi-phase structuring of perovskite crystal enabled by thermoplasmonic metasurface

Halide perovskites belong to an important family of semiconducting materials with unique electronic properties that enable a myriad of applications, especially in photovoltaics and optoelectronics. Their optical properties, including photoluminescence quantum yield, are affected and notably enhanced at crystal imperfections where the symmetry is broken and the density of states increases. These lattice distortions can be introduced through structural phase transitions, allowing charge gradients to appear near the interfaces between phase structures. In this work, we demonstrate controlled multi-phase structuring in a single perovskite crystal. The concept uses cesium lead bromine (CsPbBr3) placed on a thermoplasmonic TiN/Si metasurface and enables single, double and triple phase structures to form on demand above the room temperature. This approach opens up application horizons of dynamically controlled heterostructures with distinctive electronic and enhanced optical properties.

physics.optics

Tuning the Ultrafast Response of Fano Resonances in Halide Perovskite Nanoparticles

The full control of the fundamental photophysics of nanosystems at frequencies as high as few THz is key for tunable and ultrafast nano-photonic devices and metamaterials. Here we combine geometrical and ultrafast control of the optical properties of halide perovskite nanoparticles, which constitute a prominent platform for nanophotonics. The pulsed photoinjection of free carriers across the semiconducting gap leads to a sub-picosecond modification of the far-field electromagnetic properties that is fully controlled by the geometry of the system. When the nanoparticle size is tuned so as to achieve the overlap between the narrowband excitons and the geometry-controlled Mie resonances, the ultrafast modulation of the transmittivity is completely reversed with respect to what is usually observed in nanoparticles with different sizes, in bulk systems and in thin films. The interplay between chemical, geometrical and ultrafast tuning offers an additional control parameter with impact on nano-antennas and ultrafast optical switches.

cond-mat.mtrl-sci