176 research outputs found
Селянознавчі дослідження в контексті формування концепції Української революції 1917-1921 рр.
У статті визначені структурні складові розробки селянознавчої проблематики в контексті формування наукової концепції історії Української революції 1917-1921 рр
Trapping light with micro lenses in thin film organic photovoltaic cells.
We demonstrate a novel light trapping configuration based on an array of micro lenses in conjunction with a self aligned array of micro apertures located in a highly reflecting mirror. When locating the light trapping element, that displays strong directional asymmetric transmission, in front of thin film organic photovoltaic cells, an increase in cell absorption is obtained. By recycling reflected photons that otherwise would be lost, thinner films with more beneficial electrical properties can effectively be deployed. The light trapping element enhances the absorption rate of the solar cell and increases the photocurrent by as much as 25%. (C) 2008 Optical Society of Americ
Organic solar cells based on non-fullerene acceptors.
Organic solar cells (OSCs) have been dominated by donor:acceptor blends based on fullerene acceptors for over two decades. This situation has changed recently, with non-fullerene (NF) OSCs developing very quickly. The power conversion efficiencies of NF OSCs have now reached a value of over 13%, which is higher than the best fullerene-based OSCs. NF acceptors show great tunability in absorption spectra and electron energy levels, providing a wide range of new opportunities. The coexistence of low voltage losses and high current generation indicates that new regimes of device physics and photophysics are reached in these systems. This Review highlights these opportunities made possible by NF acceptors, and also discuss the challenges facing the development of NF OSCs for practical applications
Intermodulation electrostatic force microscopy for imaging surface photo-voltage
We demonstrate an alternative to Kelvin Probe Force Microscopy for imaging
surface potential. The open-loop, single-pass technique applies a low-frequency
AC voltage to the atomic force microscopy tip while driving the cantilever near
its resonance frequency. Frequency mixing due to the nonlinear capacitance
gives intermodulation products of the two drive frequencies near the cantilever
resonance, where they are measured with high signal to noise ratio. Analysis of
this intermodulation response allows for quantitative reconstruction of the
contact potential difference. We derive the theory of the method, validate it
with numerical simulation and a control experiment, and we demonstrate its
utility for fast imaging of the surface photo-voltage on an organic
photo-voltaic material.Comment: 4 pages, 3 figures, peer-reviewed, preprin
Особенности работы с иностранными студентами с английским языком обучения на кафедре медицинской и биологической физики
ПРЕПОДАВАТЕЛЬСКИЙ СОСТАВ УЧЕБНОГО УЧРЕЖДЕНИЯОБРАЗОВАНИЕФИЗИКА /ОБУЧИНОСТРАННЫЕ СТУДЕНТЫАНГЛИЙСКИЙ ЯЗЫК /ОБУЧМЕДИЦИНСКАЯ ФИЗИКА /ОБУЧБИОЛОГИЧЕСКАЯ ФИЗИКА /ОБУ
Формирование и развитие человеческого капитала в Республике Беларусь
Материалы XX Междунар. науч.-техн. конф. студентов, аспирантов и молодых ученых, Гомель, 23–24 апр. 2020 г
A Facile Method to Enhance Photovoltaic Performance of Benzodithiophene-Isoindigo Polymers by Inserting Bithiophene Spacer
This study describes the synthesis and characterization of four polymers based on benzo[1,2-b:4,5-b']dithiophene (BDT) and isoindigo with zero, one, two, and three thiophene spacer groups. Results have demonstrated that the use of bithiophene as a spacer unit improves the geometry of the polymer chain, making it planar, and hence, potentially enhanced π- π stacking occurs. Due to favorable interaction of the polymer chains, enhanced absorption coefficient, and optimal morphology, PBDT-BTI, which possesses bithiophene as a spacer, revealed high current and fill factor leading to a power conversion efficiency of 7.3% in devices, making this polymer the best performing isoindigo-based material in polymer solar cells (PSCs). Also, PBDT-BTI could still maintain efficiency of over 6% with the active layer thickness of 270 nm, making it a potential candidate for a material in printed PSCs. These results demonstrate that the use of thiophene spacers in D-A polymers could be an important design strategy to produce high-performance PSCs
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