arXiv subjects

Yury V. Kapitonov

Publications and source records attributed to Yury V. Kapitonov.

4 recordsLinked to original sources

arXiv2025

Fabry-Perot interferometer with quantum well mirror for controllable dispersion compensation

In this work, we investigate a possibility of controlling second-order dispersion in a monolithic Fabry-Perot interferometer based on epitaxial heterostructure with quantum well (QW) serving as a bottom mirror. Careful choice of heterostructure parameters and experimental conditions makes it possible to introduce negative dispersion in a very narrow spectral region of QW excitonic resonance while maintaining a constant reflection coefficient across this region. The feasibility of the concept is demonstrated for heterostructures with InGaAs/GaAs QWs at cryogenic temperatures. We also propose an active device design that can switch the dispersion compensation on and off by controlling the exciton ensemble's environment.

cond-mat.mes-hall↗

arXiv2023

The Faraday effect and phase transition in the CH 3 NH 3 PbI 3 halide perovskite single crystal

The spin degree of freedom of charge carriers in halide-perovskite semiconductors can be highly useful for information photonics applications. The Faraday effect is known to be the best indicator of paramagnetism of the material and of the spin-light interaction. In this work, the Faraday effect is demonstrated, for the first time, in a hybrid organic-inorganic halide perovskite MAPbI3 (MA+=CH3NH+3). The Faraday rotation and birefringence were measured across the tetragonal-cubic phase transition at 327 K. The Faraday rotation is strongly suppressed below the phase transition temperature due to anisotropy (linear birefringence) of the tetragonal crystal phase. The situation changes drastically above the phase transition temperature, when the crystal becomes optically isotropic. The emerging Faraday rotation obeys the Curie law, demonstrating its population-related paramagnetic nature. This observation opens new prospects for application of these systems and for their investigations using methods of the polarization noise spectroscopy applicable to optically anisotropic materials.

cond-mat.mtrl-sci↗

arXiv2021

Counterdiffusion-in-gel growth of high optical and crystal quality MAPbX3 (MA = CH3NH3+, X = I-, Br-) lead-halide perovskite single crystals

Halide perovskites are promising semiconductor materials for optoelectronics. One of their unique features is the synthesis, that could be performed by the crystallization from the solution. This method is fast, but practically couldn't be optimized due to the strongly non-equilibrium conditions of crystal growth. Another quality limitation is the typical incorporation of organic solvent molecules into crystals when perovskite crystallization is performed from solution with organic solvent. Here we report an alternative method of perovskite single crystal growth based on the counterdiffusion of reagents in the gel medium. This counterdiffusion-in-gel crystallization (CGC) method is based on the difference of solubility between perovskites and lead halide in the corresponding halide acid, HX. The difference of solubility between perovskites and lead halide leads to the formation of perovskite single crystals of sufficiently large size with an excellent optical quality at constant room temperature. Particularly, here we report the growth of MAPbI3 and MAPbBr3 halide perovskite single crystals (MA = CH3NH3+) by the counterdiffusion of the organic-solvent-free reagents in the U-tube filled with the silica gel. Their photoluminescence spectra recorded at 4 K demonstrate the excitonic resonances with the full width < 2.5 meV, which proves their excellent optical quality. The proposed method can be used in fabrication of high-quality halide perovskite single crystals for both fundamental research, and for applications where the absence of defects is a critical requirement.

cond-mat.mtrl-sci↗

arXiv2018

The Effect of Ga+ ion beam irradiation on the optical properties of MAPbBr3 single crystals

The effect of 30 keV Ga^+ ion beam irradiation on the low-temperature photoluminescence from a single crystal of the hybrid organic-inorganic perovskite MAPbBr3 is presented for the first time. The irradiation leads to the suppression of the crystal's excitonic luminescence starting from the dose of 10^14/cm2. However, its integral luminescence does not drop up to the doses of two orders of magnitude higher. Further increase of the irradiation dose starts to affect the integral luminescence and causes the crystal to sputter. The spatial resolution of modification by the ion beam found in the experiment is no worse than 50 μm. The theoretical resolution limit estimated by Monte-Carlo modeling using SRIM is three orders of magnitude lower. This work paves the way for the design of devices based on the spatial modulation of perovskite's excitonic properties or direct focused ion beam writing.

physics.app-ph↗