ORCID Profile
0000-0002-6396-8938
Current Organisation
ETH Zurich
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Publisher: American Chemical Society (ACS)
Date: 31-01-2023
Publisher: American Chemical Society (ACS)
Date: 17-06-2021
Publisher: American Chemical Society (ACS)
Date: 08-11-2018
DOI: 10.1021/ACS.NANOLETT.8B03027
Abstract: Fully inorganic cesium lead halide perovskite nanocrystals (NCs) have shown to exhibit outstanding optical properties such as wide spectral tunability, high quantum yield, high oscillator strength as well as blinking-free single photon emission, and low spectral diffusion. Here, we report measurements of the coherent and incoherent exciton dynamics on the 100 fs to 10 ns time scale, determining dephasing and density decay rates in these NCs. The experiments are performed on CsPbBr
Publisher: American Chemical Society (ACS)
Date: 16-03-2021
Publisher: American Chemical Society (ACS)
Date: 02-02-2015
DOI: 10.1021/NL5048779
Publisher: Springer Science and Business Media LLC
Date: 11-2021
Publisher: American Chemical Society (ACS)
Date: 28-03-2023
Publisher: Wiley
Date: 19-10-2022
Abstract: Single‐crystal halide perovskites exhibit photogenerated‐carriers of high mobility and long lifetime, making them excellent candidates for applications demanding thick semiconductors, such as ionizing radiation detectors, nuclear batteries, and concentrated photovoltaics. However, charge collection depreciates with increasing thickness therefore, tens to hundreds of volts of external bias is required to extract charges from a thick perovskite layer, leading to a considerable amount of dark current and fast degradation of perovskite absorbers. However, extending the carrier‐diffusion length can mitigate many of the anticipated issues preventing the practical utilization of perovskites in the abovementioned applications. Here, single‐crystal perovskite solar cells that are up to 400 times thicker than state‐of‐the‐art perovskite polycrystalline films are fabricated, yet retain high charge‐collection efficiency in the absence of an external bias. Cells with thicknesses of 110, 214, and 290 µm display power conversion efficiencies (PCEs) of 20.0, 18.4, and 14.7%, respectively. The remarkable persistence of high PCEs, despite the increase in thickness, is a result of a long electron‐diffusion length in those cells, which was estimated, from the thickness‐dependent short‐circuit current, to be ≈0.45 mm under 1 sun illumination. These results pave the way for adapting perovskite devices to optoelectronic applications in which a thick active layer is essential.
Publisher: American Chemical Society (ACS)
Date: 03-10-2016
Abstract: Solution-processed hybrid organic-inorganic lead halide perovskites are emerging as one of the most promising candidates for low-cost light-emitting diodes (LEDs). However, due to a small exciton binding energy, it is not yet possible to achieve an efficient electroluminescence within the blue wavelength region at room temperature, as is necessary for full-spectrum light sources. Here, we demonstrate efficient blue LEDs based on the colloidal, quantum-confined 2D perovskites, with precisely controlled stacking down to one-unit-cell thickness (n = 1). A variety of low-k organic host compounds are used to disperse the 2D perovskites, effectively creating a matrix of the dielectric quantum wells, which significantly boosts the exciton binding energy by the dielectric confinement effect. Through the Förster resonance energy transfer, the excitons down-convert and recombine radiatively in the 2D perovskites. We report room-temperature pure green (n = 7-10), sky blue (n = 5), pure blue (n = 3), and deep blue (n = 1) electroluminescence, with record-high external quantum efficiencies in the green-to-blue wavelength region.
Publisher: American Chemical Society (ACS)
Date: 20-03-2023
Publisher: American Association for the Advancement of Science (AAAS)
Date: 12-2017
Abstract: The first low-dimensional semiconductor nanocrystal system that increases the photoluminescence quantum yield in aggregates.
No related grants have been discovered for Maksym Kovalenko.