Yazar "Kara, Duygu Akin" seçeneğine göre listele

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  • Küçük Resim Yok
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    Enhanced device efficiency and long-term stability via boronic acid-based self-assembled monolayer modification of ındium tin oxide in a planar perovskite solar cell
    (AMER CHEMICAL SOC, 2018) Kara, Duygu Akin; Kara, Koray; Oylumluoglu, Gorkem; Yigit, Mesude Zeliha; Can, Mustafa; Kim, Jae Joon; Burnett, Edmund K.
    Interfacial engineering is essential for the development of highly efficient and stable solar cells through minimizing energetic losses at interfaces. Self-assembled monolayers (SAMs) have been shown as a handle to tune the work function (WF) of indium tin oxide (ITO), improving photovoltaic cell performance and device stability. In this study, we utilize a new class of boronic acid-based fluorine-terminated SAMs to modify ITO surfaces in planar perovskite solar cells. The SAM treatment demonstrates an increase of the WF of ITO, an enhancement of the short-circuit current, and a passivation of trap states at the ITO/[poly(3,4ethylenedioxylenethiophene):poly(styrenesulfonic acid)] interface. Device stability improves upon SAM modification, with efficiency decreasing only 20% after one month. Our work highlights a simple treatment route to achieve hysteresis-free, reproducible, stable, and highly efficient (16%) planar perovskite solar cells.
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    Enhancing the c-TiO2 based perovskite solar cell performance via modification by a serial of boronic acid derivative self-assembled monolayers
    (ELSEVIER, 2017) Kirbiyik, Cisem; Kara, Koray; Kara, Duygu Akin; Yigit, Mesude Zeliha; Istanbullu, Bilal; Can, Mustafa; Sariciftci, Niyazi Serdar
    Morphological control of MAPbI(3) crystal growth is one of the most important factor to fabricate high efficient perovskite solar cells. Herein, different boronic acid derivative self-assemble monolayers were used for modification of c-TiO2 surface and controlling of interface properties between c-TiO2 and MAPbI(3) layers. Pre-mixed MAPbI(3) solution in GBL was deposited by spin-coating technique onto non-modified and modified c-TiO2 surfaces by selected SAMs. The 1-OMe modified c-TiO2 based solar cell shows an increase in J(sc), resulting an increase to 9.4% PCE to compare with 5.9% PCE of non-modified c-TiO2 based solar cell. With this work, we demonstrated the possibility of morphological control of perovskite layer by using simple modification method of sublayer to increase the photovoltaic characteristics of solar cells. (C) 2017 Elsevier B.V. All rights reserved.
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    Functionalized organic semiconductor molecules to enhance charge carrier injection in electroluminescent cell
    (ELSEVIER SCIENCE BV, 2017) Yalcin, Eyyup; Kara, Duygu Akin; Karakaya, Caner; Yigit, Mesude Zeliha; Havare, Ali Kemal; Can, Mustafa; Tozlu, Cem
    Organic semiconductor (OSC) materials as a charge carrier interface play an important role to improve the device performance of organic electroluminescent cells. In this study, 4,4"-bis(diphenyl amino)-1,1':3',1"-terphenyl-5'-carboxylic acid (TPA) and 4,4"-di-9H-carbazol-9-yl-1,1':3',1"-terphenyl-5'-carboxylic acid (CAR) has been designed and synthesized to modify indium tin oxide (ITO) layer as interface. Bare ITO and PEDOT:PSS coated on ITO was used as reference anode electrodes for comparison. Furthermore, PEDOT:PSS coated over CAR/ITO and TPA/ITO to observe stability of OSC molecules and to completely cover the ITO surface. Electrical, optical and surface characterizations were performed for each device. Almost all modified devices showed around 36% decrease at the turn on voltage with respect to bare ITO. The current density of bare ITO, ITO/CAR and ITO/TPA were measured as 288, 1525 and 1869 A/m(2), respectively. By increasing current density, luminance of modified devices showed much better performance with respect to unmodified devices. (C) 2017 Elsevier B.V. All rights reserved.