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Ciesielski A, Iwański J, Wróbel P, Bożek R, Kret S, Turczyński J, Binder J, Korona KP, Stępniewski R, Wysmołek A. All-BN distributed Bragg reflectors fabricated in a single MOCVD process. Nanotechnology 2023; 35:055202. [PMID: 37879328 DOI: 10.1088/1361-6528/ad06d1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 10/25/2023] [Indexed: 10/27/2023]
Abstract
Distributed Bragg Reflectors (DBR) are well-established photonic structures that are used in many photonic applications. However, most of the DBRs are based on different materials or require post-process etching which can hinder integration with other components in the final photonic structure. Here, we demonstrate the fabrication of DBR structures consisting only of undoped boron nitride (BN) layers with high refractive index contrast by using metal-organic chemical vapor deposition (MOCVD). This has been achieved in a single process, without the need for any post-process etching. The difference in the refractive index of the component BN layers stems from different degrees of porosity of the individual BN layers, which is a direct result of a different growth temperature. The fabricated DBR structures consist of 15.5 pairs of BN layers and exhibit a reflectance of 87 ± 1% at the maximum. The wavelength of maximum reflectance can be tuned from 500 nm up to the infrared region (IR), by simply adjusting the growth periods of subsequent BN layers. We also demonstrate that the fabricated structures can be used to create an optical microcavity. The fabricated DBRs are very promising candidates for future applications, for example in combination with single-photon emitters in h-BN, which could allow the building of a cavity-based all-BN single-photon source.
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Affiliation(s)
| | - Jakub Iwański
- University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw, Poland
| | - Piotr Wróbel
- University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw, Poland
| | - Rafał Bożek
- University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw, Poland
| | - Sławomir Kret
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland
| | - Jakub Turczyński
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland
| | - Johannes Binder
- University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw, Poland
| | - Krzysztof P Korona
- University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw, Poland
| | - Roman Stępniewski
- University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw, Poland
| | - Andrzej Wysmołek
- University of Warsaw, Faculty of Physics, Pasteura 5, 02-093 Warsaw, Poland
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2
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Korona KP, Binder J, Dąbrowska AK, Iwański J, Reszka A, Korona T, Tokarczyk M, Stępniewski R, Wysmołek A. Growth temperature induced changes of luminescence in epitaxial BN: from colour centres to donor-acceptor recombination. Nanoscale 2023. [PMID: 37227414 DOI: 10.1039/d3nr00578j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Defects play a very important role in semiconductors and only the control over the defect properties allows the implementation of materials in dedicated applications. We present an investigation of the UV luminescence of defects in hexagonal boron nitride (h-BN) grown by Metal Organic Vapor Phase Epitaxy (MOVPE). Such intentionally introduced defects are important for applications like deep UV emission and quantum information. In this work, we performed photoluminescence and cathodoluminescence experiments on a set of h-BN layers grown by MOVPE at different growth temperatures (tgr). The obtained defect-related spectra in the ultraviolet range include well-known lines at about 230 nm (X230, hν = 5.4 eV) and 300 nm (C300 - the brightest one, hν = 4.14 eV) as well as a rarely observed band with a zero-phonon line at 380 nm (C380, hν = 3.24 eV). The C300 and C380 bands have the characteristic of a color centre showing sharp lines (0.6 nm width) at 5 K. These lines are most probably an internal transition of carbon-related defects. We show that for samples grown at high temperatures (tgr > 1200 °C), the lines related to the color centres C are replaced by broad bands at 330 nm and 400 nm, which we marked as D330 and D400, respectively. The D bands have similar central energies to the C bands but extend over a large energy range, so we propose that the D emission is due to a shallow donor to deep acceptor recombination. Time-resolved photoluminescence analysis determined the lifetimes of the individual lines in the range from 0.9 ns (C300), 1.8 ns (C380) to 4 ns (D400). The C300 and C380 color centre bands are composed of a series of characteristic lines that are due to the interaction with phonons. The E1u (198 meV) and A2u (93 meV) phonon replicas have been identified.
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Affiliation(s)
- K P Korona
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
| | - J Binder
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
| | - A K Dąbrowska
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
| | - J Iwański
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
| | - A Reszka
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland
| | - T Korona
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - M Tokarczyk
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
| | - R Stępniewski
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
| | - A Wysmołek
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
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3
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Wincukiewicz A, Wierzyńska E, Bohdan A, Tokarczyk M, Korona KP, Skompska M, Kamińska M. Enhanced Performance of Camphorsulfonic Acid-Doped Perovskite Solar Cells. Molecules 2022; 27:molecules27227850. [PMID: 36431947 PMCID: PMC9699157 DOI: 10.3390/molecules27227850] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 11/10/2022] [Accepted: 11/12/2022] [Indexed: 11/16/2022]
Abstract
High-quality perovskite film with large grains and therefore reduced grain boundaries plays a significant role in improving the power conversion efficiency (PCE) and ensuring good long-term stability of the perovskite solar cells. In this work, we found that adding camphorsulfonic acid (CSA), a Lewis base, to the perovskite solution results in the crystallization of larger perovskite grains. By varying the concentration of CSA, we found that the optimal concentration of the additive is 1 mg/mL, which leads to an 20% increase in PCE of the cells compared to the reference CSA-free cell. Interestingly, we observed that the PCE of cells with an excess of CSA was initially poor, but may increase significantly over time, possibly due to CSA migration to the hole-transporting layer, leading to an improvement in its conductivity.
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Affiliation(s)
- Adam Wincukiewicz
- Faculty of Physics, University of Warsaw, Pasteur 5, 02-093 Warsaw, Poland
| | - Ewelina Wierzyńska
- Faculty of Chemistry, University of Warsaw, Pasteur 1, 02-093 Warsaw, Poland
| | - Aliaksei Bohdan
- Faculty of Physics, University of Warsaw, Pasteur 5, 02-093 Warsaw, Poland
| | - Mateusz Tokarczyk
- Faculty of Physics, University of Warsaw, Pasteur 5, 02-093 Warsaw, Poland
| | | | - Magdalena Skompska
- Faculty of Chemistry, University of Warsaw, Pasteur 1, 02-093 Warsaw, Poland
| | - Maria Kamińska
- Faculty of Physics, University of Warsaw, Pasteur 5, 02-093 Warsaw, Poland
- Correspondence:
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4
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Krajewski M, Piotrowski P, Mech W, Korona KP, Wojtkiewicz J, Pilch M, Kaim A, Drabińska A, Kamińska M. Optical Properties and Light-Induced Charge Transfer in Selected Aromatic C60 Fullerene Derivatives and in Their Bulk Heterojunctions with Poly(3-Hexylthiophene). Materials (Basel) 2022; 15:6908. [PMID: 36234249 PMCID: PMC9571621 DOI: 10.3390/ma15196908] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/26/2022] [Accepted: 09/28/2022] [Indexed: 06/16/2023]
Abstract
Fullerene derivatives offer great scope for modification of the basic molecule, often called a buckyball. In recent years, they have been the subject of numerous studies, in particular in terms of their applications, including in solar cells. Here, the properties of four recently synthesized fullerene C60 derivatives were examined regarding their optical properties and the efficiency of the charge transfer process, both in fullerene derivatives themselves and in their heterojunctions with poly (3-hexylthiophene). Optical absorption, electron spin resonance (ESR), and time-resolved photoluminescence (TRPL) techniques were applied to study the synthesized molecules. It was shown that the absorption processes in fullerene derivatives are dominated by absorption of the fullerene cage and do not significantly depend on the type of the derivative. It was also found by ESR and TRPL studies that asymmetrical, dipole-like derivatives exhibit stronger light-induced charge transfer properties than their symmetrical counterparts. The observed inhomogeneous broadening of the ESR lines indicated a large disorder of all polymer-fullerene derivative blends. The density functional theory was applied to explain the results of the optical absorption experiments.
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Affiliation(s)
- Maciej Krajewski
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Piotr Piotrowski
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Wojciech Mech
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | | | - Jacek Wojtkiewicz
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Marek Pilch
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Andrzej Kaim
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Aneta Drabińska
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Maria Kamińska
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
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5
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Kulszewicz-Bajer I, Nowakowski R, Zagórska M, Maranda-Niedbała A, Mech W, Wróbel Z, Drapała J, Wielgus I, Korona KP. Copolymers Containing 1-Methyl-2-phenyl-imidazole Moieties as Permanent Dipole Generating Units: Synthesis, Spectroscopic, Electrochemical, and Photovoltaic Properties. Molecules 2022; 27:molecules27030915. [PMID: 35164178 PMCID: PMC8840365 DOI: 10.3390/molecules27030915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 12/10/2022] Open
Abstract
New donor–acceptor conjugated alternating or random copolymers containing 1-methyl-2-phenylbenzimidazole and benzothiadiazole (P1), diketopyrrolopyrrole (P4), or both acceptors (P2) are reported. The specific feature of these copolymers is the presence of a permanent dipole-bearing moiety (1-methyl-2-phenyl imidazole (MPI)) fused with the 1,4-phenylene ring of the polymer main chain. For comparative reasons, polymers of the same main chain but deprived of the MPI group were prepared, namely, P5 with diketopyrrolopyrrole and P3 with both acceptors. The presence of the permanent dipole results in an increase of the optical band gap from 1.51 eV in P3 to 1.57 eV in P2 and from 1.49 eV in P5 to 1.55 eV in P4. It also has a measurable effect on the ionization potential (IP) and electrochemical band gap (EgCV), leading to their decrease from 5.00 and 1.83 eV in P3 to 4.92 and 1.79 eV in P2 as well as from 5.09 and 1.87 eV in P5 to 4.94 and 1.81 eV in P4. Moreover, the presence of permanent dipole lowers the exciton binding energy (Eb) from 0.32 eV in P3 to 0.22 eV in P2 and from 0.38 eV in P5 to 0.26 eV in P4. These dipole-induced changes in the polymer properties should be beneficial for photovoltaic applications. Bulk heterojunction solar cells fabricated from these polymers (with PC71BM acceptor) show low series resistance (rs), indicating good electrical transport properties. The measured power conversion efficiency (PCE) of 0.54% is limited by the unfavorable morphology of the active layer.
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Affiliation(s)
- Irena Kulszewicz-Bajer
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland; (J.D.); (I.W.)
- Correspondence: (I.K.-B.); (M.Z.)
| | - Robert Nowakowski
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland; (R.N.); (A.M.-N.)
| | - Małgorzata Zagórska
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland; (J.D.); (I.W.)
- Correspondence: (I.K.-B.); (M.Z.)
| | - Agnieszka Maranda-Niedbała
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland; (R.N.); (A.M.-N.)
| | - Wojciech Mech
- Faculty of Physics, Warsaw University, Pasteura 5, 02-093 Warsaw, Poland; (W.M.); (K.P.K.)
| | - Zbigniew Wróbel
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland;
| | - Jakub Drapała
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland; (J.D.); (I.W.)
| | - Ireneusz Wielgus
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland; (J.D.); (I.W.)
| | - Krzysztof P. Korona
- Faculty of Physics, Warsaw University, Pasteura 5, 02-093 Warsaw, Poland; (W.M.); (K.P.K.)
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6
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Jewłoszewicz B, Bogdanowicz KA, Przybył W, Dysz K, Dylong A, Gonciarz A, Pich R, Mech W, Korona KP, Kamińska M, Zarębska K, Skompska M, Kaim A, Ciesielski A, Iwan A. A comprehensive optical and electrical study of unsymmetrical imine with four thiophene rings and their binary and ternary compositions with PTB7 and PC 70BM towards organic photovoltaics. RSC Adv 2020; 10:44958-44972. [PMID: 35516284 PMCID: PMC9058665 DOI: 10.1039/d0ra08330e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 11/25/2020] [Indexed: 12/21/2022] Open
Abstract
A new unsymmetrical imine with four thiophene rings was synthesized in a one-step reaction, starting from the commercially available and relatively inexpensive reagents. The obtained imine in the form of thin films exhibited photoluminescence properties in the 1.8–2.4 eV energy range and a photoluminescence lifetime of about 0.3 ns. The HOMO and LUMO levels of the imine determined by cyclic voltammetry were at about −5.19 eV and −3.05 eV, respectively. The density functional theory was applied to calculate the geometric and electronic structure of the imine. The UV-Vis spectra showed that the absorption range of the imine overlaps with that of PC70BM, and the absorption peak at the maximum of the imine at 424 nm is located between the two maxima at 404 nm and 461 nm of the fullerene derivative. The electron acceptor and donor activity of the imine was tested in the solar cell architecture: glass/ITO/PEDOT:PSS/active layer/In/Al. The best photovoltaic parameters, with very good reproducibility for each 8 pixels in the cell, were found for the active layer based on ternary mixture PTB7:PC70BM:imine at a weight ratio 8 : 13 : 1, with the power conversion efficiency of about 4%. The external quantum efficiency of devices with the imine was found to be about 40% at 3.3 eV. The thermal imaging together with the recorded current response at increasing potential showed that the presence of imine in the composition has a beneficial impact in terms of current flow stability at temperatures above 200 °C, compared to two component layers with the same imine as an additive. A new unsymmetrical imine with four thiophene rings was synthesized in a one-step reaction, starting from the commercially available and relatively inexpensive reagents.![]()
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Affiliation(s)
- Beata Jewłoszewicz
- Military Institute of Engineer Technology Obornicka 136 Str. 50-961 Wroclaw Poland
| | | | - Wojciech Przybył
- Military Institute of Engineer Technology Obornicka 136 Str. 50-961 Wroclaw Poland
| | - Karolina Dysz
- Military Institute of Engineer Technology Obornicka 136 Str. 50-961 Wroclaw Poland
| | - Agnieszka Dylong
- Military Institute of Engineer Technology Obornicka 136 Str. 50-961 Wroclaw Poland
| | - Agnieszka Gonciarz
- Faculty of Security and Safety Research, General Tadeusz Kosciuszko Military University of Land Forces Czajkowskiego 109 Str. 51-147 Wroclaw Poland
| | - Robert Pich
- Faculty of Security and Safety Research, General Tadeusz Kosciuszko Military University of Land Forces Czajkowskiego 109 Str. 51-147 Wroclaw Poland
| | - Wojciech Mech
- Faculty of Physics, University of Warsaw Pasteura 5 02-093 Warsaw Poland
| | - Krzysztof P Korona
- Faculty of Physics, University of Warsaw Pasteura 5 02-093 Warsaw Poland
| | - Maria Kamińska
- Faculty of Physics, University of Warsaw Pasteura 5 02-093 Warsaw Poland
| | - Kamila Zarębska
- Faculty of Chemistry, University of Warsaw Pasteura 1 02-093 Warsaw Poland
| | - Magdalena Skompska
- Faculty of Chemistry, University of Warsaw Pasteura 1 02-093 Warsaw Poland
| | - Andrzej Kaim
- Faculty of Chemistry, University of Warsaw Pasteura 1 02-093 Warsaw Poland
| | | | - Agnieszka Iwan
- Military Institute of Engineer Technology Obornicka 136 Str. 50-961 Wroclaw Poland
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7
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Tchutchulashvili G, Chusnutdinow S, Mech W, Korona KP, Reszka A, Sobanska M, Zytkiewicz ZR, Sadowski W. GaN Nanowire Array for Charge Transfer in Hybrid GaN/P3HT:PC 71BM Photovoltaic Heterostructure Fabricated on Silicon. Materials (Basel) 2020; 13:ma13214755. [PMID: 33114337 PMCID: PMC7662278 DOI: 10.3390/ma13214755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 10/14/2020] [Accepted: 10/21/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate that a GaN nanowire array can be used for efficient charge transfer between the organic photovoltaic layer and silicon in a Si/GaN/P3HT:PC71BM inverted hybrid heterostructure. The band alignment of such a material combination is favorable to facilitate exciton dissociation, carrier separation and electron transport into Si. The ordered nature of the GaN array helps to mitigate the intrinsic performance limitations of the organic active layer. The dependence of photovoltaic performance enhancement on the morphology of the nanostructure with nanowire diameters 30, 50, 60, 100 and 150 nm was studied in detail. The short circuit current was enhanced by a factor of 4.25, while an open circuit voltage increase by 0.32 volts was achieved compared to similar planar layers.
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Affiliation(s)
- Giorgi Tchutchulashvili
- Faculty of Applied Physics and Mathematics, Gdansk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdansk, Poland;
| | - Sergij Chusnutdinow
- Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland; (S.C.); (A.R.); (M.S.); (Z.R.Z.)
| | - Wojciech Mech
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland; (W.M.); (K.P.K.)
| | - Krzysztof P. Korona
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland; (W.M.); (K.P.K.)
| | - Anna Reszka
- Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland; (S.C.); (A.R.); (M.S.); (Z.R.Z.)
| | - Marta Sobanska
- Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland; (S.C.); (A.R.); (M.S.); (Z.R.Z.)
| | - Zbigniew R. Zytkiewicz
- Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland; (S.C.); (A.R.); (M.S.); (Z.R.Z.)
| | - Wojciech Sadowski
- Faculty of Applied Physics and Mathematics, Gdansk University of Technology, Gabriela Narutowicza 11/12, 80-233 Gdansk, Poland;
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8
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Ogorzałek Z, Seredyński B, Kret S, Kwiatkowski A, Korona KP, Grzeszczyk M, Mierzejewski J, Wasik D, Pacuski W, Sadowski J, Gryglas-Borysiewicz M. Charge transport in MBE-grown 2H-MoTe 2 bilayers with enhanced stability provided by an AlO x capping layer. Nanoscale 2020; 12:16535-16542. [PMID: 32790820 DOI: 10.1039/d0nr03148h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Thin layers of transition metal dichalcogenides have been intensively studied over the last few years due to their novel physical phenomena and potential applications. One of the biggest problems in laboratory handling and moving on to application-ready devices lies in the high sensitivity of their physicochemical properties to ambient conditions. We demonstrate that novel, in situ capping with an ultra-thin, aluminum film efficiently protects thin MoTe2 layers stabilizing their electronic transport properties after exposure to ambient conditions. The experiments have been performed on bilayers of 2H-MoTe2 grown by molecular beam epitaxy on large area GaAs(111)B substrates. The crystal structure, surface morphology and thickness of the deposited MoTe2 layers have been precisely controlled in situ with a reflection high energy electron diffraction system. As evidenced by high resolution transmission electron microscopy, MoTe2 films exhibit perfect arrangement in the 2H phase and the epitaxial relation to the GaAs(111)B substrates. After the growth, the samples were in situ capped with a thin (3 nm) film of aluminum, which oxidizes after exposure to ambient conditions. This oxide serves as a protective layer to the underlying MoTe2. Resistivity measurements of the MoTe2 layers with and without the cap, exposed to low vacuum, nitrogen and air, revealed a huge difference in their stability. The significant rise of resistance is observed for the unprotected sample while the resistance of the protected one is constant. Wide range temperature resistivity studies showed that charge transport in MoTe2 is realized by hopping with an anomalous hopping exponent of x ≃ 0.66, reported also previously for ultra-thin, metallic layers.
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Affiliation(s)
- Zuzanna Ogorzałek
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093, Warsaw, Poland.
| | | | - Sławomir Kret
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, 02-668, Warsaw, Poland
| | - Adam Kwiatkowski
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093, Warsaw, Poland.
| | - Krzysztof P Korona
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093, Warsaw, Poland.
| | | | - Janusz Mierzejewski
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093, Warsaw, Poland.
| | - Dariusz Wasik
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093, Warsaw, Poland.
| | - Wojciech Pacuski
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093, Warsaw, Poland.
| | - Janusz Sadowski
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093, Warsaw, Poland. and Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, 02-668, Warsaw, Poland and Department of Physics and Electrical Engineering, Linnaeus University, SE-391 82, Kalmar, Sweden
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9
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Korona KP, Zytkiewicz ZR, Sobanska M, Sosada FE, Dróżdż PA, Klosek K, Tchutchulashvili G. Reflectance and fast polarization dynamics of a GaN/Si nanowire ensemble. J Phys Condens Matter 2018; 30:315301. [PMID: 29939153 DOI: 10.1088/1361-648x/aacedd] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Optical phenomena in an ensemble of high-quality GaN nanowires (NWs) grown on a Si substrate have been studied by reflectance and time-resolved luminescence. Such NWs form a structure that acts as a virtual layer that specifically reflects and polarizes light and can be characterized by an effective refractive index. In fact we have found that the NW ensembles of high NW density (high filling fraction) behave rather like a layer of effective medium described by the Maxwell Garnett approximation. Moreover, light extinction and strong depolarization are observed that we assign to scattering and interference of light inside the NW ensemble. The wavelength range of high extinction and depolarization correlates well with transverse localization wavelength estimated for such an ensemble of NWs, so we suppose that these effects are due to Anderson localization of light. We also report results of time-resolved measurements of polarization of individual emission centers including free and bound excitons (D0XA, 3.47 eV), inversion domain boundaries (IDB, 3.45 eV) and stacking faults (SF, 3.42 eV). The emission of the D0XA and SF lines is polarized perpendicular to GaN c-axis while the 3.45 eV line is polarized along the c-axis which supports a hypothesis that this line is emitted from IDBs. Time-dependent depolarization of luminescence is observed during the first 0.1 ns after excitation and is interpreted as the result of interaction of the emission centers with hot particles existing for a short time after excitation.
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Affiliation(s)
- K P Korona
- Faculty of Physics, Institute of Experimental Physics, University of Warsaw, ul. Pasteura 5, 02-923 Warsaw, Poland
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10
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Michalska M, Iwan A, Andrzejczuk M, Roguska A, Sikora A, Boharewicz B, Tazbir I, Hreniak A, Popłoński S, Korona KP. Analysis of the surface decoration of TiO2 grains using silver nanoparticles obtained by ultrasonochemical synthesis towards organic photovoltaics. NEW J CHEM 2018. [DOI: 10.1039/c7nj05180h] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The wet ultrasonochemical method was used to obtained TiO2/n-Ag nanoparticles for polymer solar cells.
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Affiliation(s)
| | - Agnieszka Iwan
- General Tadeusz Kosciuszko Military University of Land Forces, Wroclaw; MULF Wroclaw, Faculty of Security and Safety Research
- 51-147 Wroclaw
- Poland
| | - Mariusz Andrzejczuk
- Faculty of Materials Engineering, Warsaw University of Technology
- 02-507 Warsaw
- Poland
| | - Agata Roguska
- Institute of Physical Chemistry, Polish Academy of Sciences
- 01-224 Warsaw
- Poland
| | - Andrzej Sikora
- Electrotechnical Institute, Division of Electrotechnology and Materials Science
- 50-369 Wroclaw
- Poland
| | - Bartosz Boharewicz
- Electrotechnical Institute, Division of Electrotechnology and Materials Science
- 50-369 Wroclaw
- Poland
| | - Igor Tazbir
- Electrotechnical Institute, Division of Electrotechnology and Materials Science
- 50-369 Wroclaw
- Poland
| | - Agnieszka Hreniak
- Electrotechnical Institute, Division of Electrotechnology and Materials Science
- 50-369 Wroclaw
- Poland
| | - Sebastian Popłoński
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw
- 02- 093 Warsaw
- Poland
| | - Krzysztof P. Korona
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw
- 02- 093 Warsaw
- Poland
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Iwan A, Boharewicz B, Tazbir I, Filapek M, Korona KP, Wróbel P, Stefaniuk T, Ciesielski A, Wojtkiewicz J, Wronkowska AA, Wronkowski A, Zboromirska-Wnukiewicz B, Grankowska-Ciechanowicz S, Kaminska M, Szoplik T. How do 10-camphorsulfonic acid, silver or aluminum nanoparticles influence optical, electrochemical, electrochromic and photovoltaic properties of air and thermally stable triphenylamine-based polyazomethine with carbazole moieties? Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.10.110] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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12
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Michalska M, Krajewski M, Ziolkowska D, Hamankiewicz B, Andrzejczuk M, Lipinska L, Korona KP, Czerwinski A. Influence of milling time in solid-state synthesis on structure, morphology and electrochemical properties of Li4Ti5O12 of spinel structure. POWDER TECHNOL 2014. [DOI: 10.1016/j.powtec.2014.06.056] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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13
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Borysiuk J, Zytkiewicz ZR, Sobanska M, Wierzbicka A, Klosek K, Korona KP, Perkowska PS, Reszka A. Growth by molecular beam epitaxy and properties of inclined GaN nanowires on Si(001) substrate. Nanotechnology 2014; 25:135610. [PMID: 24598248 DOI: 10.1088/0957-4484/25/13/135610] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The growth mode and structural and optical properties of novel type of inclined GaN nanowires (NWs) grown by plasma-assisted MBE on Si(001) substrate were investigated. We show that due to a specific nucleation mechanism the NWs grow epitaxially on the Si substrate without any Si(x)N(y) interlayer, first in the form of zinc-blende islands and then as double wurtzite GaN nanorods with Ga-polarity. X-ray measurements show that orientation of these nanowires is epitaxially linked to the symmetry of the substrate so that [0001] axis of w-GaN nanowire is directed along the [111]Si axis. This is different from commonly observed behavior of self-induced GaN NWs that are N-polar and grow perpendicularly to the surface of nitridized silicon substrate independently on its orientation. The inclined NWs exhibit bright luminescence of bulk donor-bound excitons (D(0)X) at 3.472 eV and exciton-related peak at 3.46 eV having a long lifetime (0.7 ns at 4 K) and observable up to 50 K.
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Affiliation(s)
- J Borysiuk
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, 02-668 Warsaw, Poland. Faculty of Physics, University of Warsaw, Hoza 69, 00-681 Warsaw, Poland
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14
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Papierska J, Witkowski BS, Derkachova A, Korona KP, Binder J, Gałkowski K, Wachnicki Ł, Godlewski M, Dietl T, Suffczyński J. Modification of Emission Properties of ZnO Layers due to Plasmonic Near-Field Coupling to Ag Nanoislands. Plasmonics 2013; 8:913-919. [PMID: 23662095 PMCID: PMC3646165 DOI: 10.1007/s11468-013-9490-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 01/30/2013] [Indexed: 05/29/2023]
Abstract
A simple fabrication method of silver (Ag) nanoislands on ZnO films is presented. Continuous wave and time-resolved photoluminescence and transmission are employed to investigate modifications of visible and UV emissions of ZnO brought about by coupling to localized surface plasmons residing on Ag nanoislands. The size of the nanoislands, determining their absorption and scattering efficiencies, is found to be an important factor governing plasmonic modification of optical response of ZnO films. The presence of the Ag nanoislands of appropriate dimensions causes a strong (threefold) increase in emission intensity and up to 1.5 times faster recombination. The experimental results are successfully described by model calculations within the Mie theory.
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Affiliation(s)
- Joanna Papierska
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69 St., 00-681 Warszawa, Poland
| | - Bartłomiej S. Witkowski
- Institute of Physics, Polish Academy of Sciences, Lotników 32/46 Av., 02-668 Warszawa, Poland
| | - Anastasiya Derkachova
- Institute of Physics, Polish Academy of Sciences, Lotników 32/46 Av., 02-668 Warszawa, Poland
| | - Krzysztof P. Korona
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69 St., 00-681 Warszawa, Poland
| | - Johannes Binder
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69 St., 00-681 Warszawa, Poland
| | - Krzysztof Gałkowski
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69 St., 00-681 Warszawa, Poland
| | - Łukasz Wachnicki
- Institute of Physics, Polish Academy of Sciences, Lotników 32/46 Av., 02-668 Warszawa, Poland
| | - Marek Godlewski
- Institute of Physics, Polish Academy of Sciences, Lotników 32/46 Av., 02-668 Warszawa, Poland
| | - Tomasz Dietl
- Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, Hoża 69 St., 00-681 Warszawa, Poland
- Institute of Physics, Polish Academy of Sciences, Lotników 32/46 Av., 02-668 Warszawa, Poland
| | - Jan Suffczyński
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoża 69 St., 00-681 Warszawa, Poland
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15
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Jasinski JB, Ziolkowska D, Michalska M, Lipinska L, Korona KP, Kaminska M. Novel graphene oxide/manganese oxide nanocomposites. RSC Adv 2013. [DOI: 10.1039/c3ra42254b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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16
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Wolos A, Piersa M, Strzelecka G, Korona KP, Hruban A, Kaminska M. Mn configuration in III-V semiconductors and its influence on electric transport and semiconductor magnetism. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/pssc.200982521] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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