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N. G. Park - One of the best experts on this subject based on the ideXlab platform.
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Green solvent for Perovskite Solar Cell production
Nature Sustainability, 2020Co-Authors: N. G. ParkAbstract:Perovskite Solar Cell (PSC) technology is moving closer to commercialization but the ecotoxicity of the solvents involved in Perovskite processing remains a barrier. A study now identifies a green solvent that can help PSC sustainability and scalability.
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Crystal growth engineering for high efficiency Perovskite Solar Cells
CrystEngComm, 2016Co-Authors: N. G. ParkAbstract:The Perovskite Solar Cell is based on organic–inorganic lead halides such as methylammonium CH3NH3PbI3 or formamidinium HC(NH2)2PbI3 as light harvesters. Since the first report on a long-term, durable, 9.7% efficient solid-state Perovskite Solar Cell in 2012, the Perovskite Solar Cell has received great attention because of facile processing and superb photovoltaic performance. As a result, a power conversion efficiency exceeding 22% was certified in 2016. To achieve a high efficiency Perovskite Solar Cell, understanding the crystal structure and opto-electronic properties of organic–inorganic lead halide Perovskites are of importance. Growth of Perovskite on substrate without traps and grain boundaries is equally important for attaining high efficiency. In this article, the emergence of the Perovskite Solar Cell, the structural and opto-electronic characteristics of Perovskite materials and the methodologies of Perovskite crystal growth both from solution and on a substrate are reviewed.
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Methodologies for high efficiency Perovskite Solar Cells
Nano Convergence, 2016Co-Authors: N. G. ParkAbstract:Since the report on long-term durable solid-state Perovskite Solar Cell in 2012, Perovskite Solar Cells based on lead halide Perovskites having organic cations such as methylammonium CH3NH3PbI3 or formamidinium HC(NH2)2PbI3 have received great attention because of superb photovoltaic performance with power conversion efficiency exceeding 22 %. In this review, emergence of Perovskite Solar Cell is briefly introduced. Since understanding fundamentals of light absorbers is directly related to their photovoltaic performance, opto-electronic properties of organo lead halide Perovskites are investigated in order to provide insight into design of higher efficiency Perovskite Solar Cells. Since the conversion efficiency of Perovskite Solar Cell is found to depend significantly on Perovskite film quality, methodologies for fabricating high quality Perovskite films are particularly emphasized, including various solution-processes and vacuum deposition method.
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control of i v hysteresis in ch3nh3pbi3 Perovskite Solar Cell
Journal of Physical Chemistry Letters, 2015Co-Authors: Inhyuk Jang, Mansoo Choi, Antonio Guerrero, Juan Bisquert, N. G. ParkAbstract:Mismatch of current (I)-voltage (V) curves with respect to the scan direction, so-called I–V hysteresis, raises critical issue in MAPbI3 (MA = CH3NH3) Perovskite Solar Cell. Although ferroelectric and ion migration have been proposed as a basis for the hysteresis, origin of hysteresis has not been apparently unraveled. We report here on the origin of I–V hysteresis of Perovskite Solar Cell that was systematically evaluated by the interface-dependent electrode polarizations. Frequency (f)-dependent capacitance (C) revealed that the normal planar structure with the TiO2/MAPbI3/spiro-MeOTAD configuration showed most significant I–V hysteresis along with highest capacitance (10–2 F/cm2) among the studied Cell configurations. Substantial reduction in capacitance to 10–3 F/cm2 was observed upon replacing TiO2 with PCBM, indicative of the TiO2 layer being mainly responsible for the hysteresis. The capacitance was intensively reduced to 10–5 F/cm2 and C–f feature shifted to higher frequency for the hysteresis-fre...
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Effects of Seed Layer on Growth of ZnO Nanorod and Performance of Perovskite Solar Cell
The Journal of Physical Chemistry C, 2015Co-Authors: Dae-yong Son, Kyeong-hui Bae, Hui-seon Kim, N. G. ParkAbstract:Effects of seed layer on growth of ZnO nanorod and photovoltaic performance of Perovskite Solar Cell were investigated. Three different coating solutions (the clear solution, the colloidal solution, and the nano-powder dispersed solution) were prepared for making seed layers. Vertically aligned ZnO nanorods were grown on the colloidal-based seed layer, while tilted nanorods were obtained on the solution- and powder-based seed layers. Open-circuit voltage (Voc) of the CH3NH3PbI3 Perovskite Solar Cell was predominantly influenced by the seed layers, where highest Voc was obtained from the ZnO nanorod grown on the colloidal seed layer. Impedance spectroscopic study revealed that recombination resistances at the seed layer contact and the ZnO nanorod/Perovskite interface were increased by the colloidal coating, which was responsible for the enhanced Voc. Surface modification of ZnO nanorods improved further Voc and fill factor, leading to power conversion efficiency of 14.35%. This work emphasizes that the se...
Hongwei Han - One of the best experts on this subject based on the ideXlab platform.
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Efficient Compact-Layer-Free, Hole-Conductor-Free, Fully Printable Mesoscopic Perovskite Solar Cell
The journal of physical chemistry letters, 2016Co-Authors: Xixi Jiang, Yuli Xiong, Yaoguang Rong, Anyi Mei, Li Hong, Yingxia Jin, Qingju Liu, Hongwei HanAbstract:A compact-layer-free, hole-conductor-free, fully printable mesoscopic Perovskite Solar Cell presents a power conversion efficiency of over 13%, which is comparable to that of the device with a TiO2 compact layer. The different wettability of the Perovskite precursor solution on the surface of FTO and TiO2 possesses a significant effect on realizing efficient mesoscopic Perovskite Solar Cell. This result shows a promising future in printable Solar Cells by further simplifying the fabrication process and lowering the preparation costs.
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a hole conductor free fully printable mesoscopic Perovskite Solar Cell with high stability
Science, 2014Co-Authors: Anyi Mei, Yaoguang Rong, Michael Gratzel, Linfeng Liu, Tongfa Liu, Jiangzhao Chen, Ying Yang, Hongwei HanAbstract:We fabricated a Perovskite Solar Cell that uses a double layer of mesoporous TiO2 and ZrO2 as a scaffold infiltrated with Perovskite and does not require a hole-conducting layer. The Perovskite was produced by drop-casting a solution of PbI2, methylammonium (MA) iodide, and 5-ammoniumvaleric acid (5-AVA) iodide through a porous carbon film. The 5-AVA templating created mixed-cation Perovskite (5-AVA)x(MA)1- xPbI3 crystals with lower defect concentration and better pore filling as well as more complete contact with the TiO2 scaffold, resulting in a longer exciton lifetime and a higher quantum yield for photoinduced charge separation as compared to MAPbI3. The Cell achieved a certified power conversion efficiency of 12.8% and was stable for >1000 hours in ambient air under full sunlight.
Ayesha Imtiaz - One of the best experts on this subject based on the ideXlab platform.
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A novel leaves and needles like TiO2 (LNT) electron transfer layer (ETL) as an alternative to meso-porous TiO2 electron transfer layer (ETL) in Perovskite Solar Cell
Optical Materials, 2020Co-Authors: Hamid Latif, Zuha Azher, Syeda Ammara Shabbir, Saba Rasheed, Erum Pervaiz, Abdul Sattar, Ayesha ImtiazAbstract:Abstract Two Perovskite Solar Cells one with leaves and needles like TiO2 (LNT) and other with meso-porous TiO2 as electron transfer layer (ETL) were fabricated. The Perovskite Solar Cell structure FTO/Compact-TiO2/LNT/CH3NH3PbBr3/Spiro-OMeTAD/Ag with leaves and needles like TiO2 electron collector, exhibit high efficiency up to 9% being supported by high open-circuit voltage and fill factor up to 0.8 V and 0.89, respectively. The second Perovskite Solar Cell structure FTO/Compact-TiO2/Meso-porous TiO2/CH3NH3PbBr3/Spiro-OMeTAD/Ag with meso-porous TiO2 electron collector, efficiency is 6.2% with open-circuit voltage and fill factor up to 0.77 V and 0.71 respectively. As compared to meso-porous TiO2 electron collector layer, leaves and needles like TiO2 has better electron band alignment with compact TiO2 as hole blocking layer and hence, results in higher efficiency.
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A novel leaves and needles like TiO2 (LNT) electron transfer layer (ETL) as an alternative to meso-porous TiO2 electron transfer layer (ETL) in Perovskite Solar Cell
Optical Materials, 2020Co-Authors: Hamid Latif, Zuha Azher, Syeda Ammara Shabbir, Saba Rasheed, Erum Pervaiz, Abdul Sattar, Ayesha ImtiazAbstract:Abstract Two Perovskite Solar Cells one with leaves and needles like TiO2 (LNT) and other with meso-porous TiO2 as electron transfer layer (ETL) were fabricated. The Perovskite Solar Cell structure FTO/Compact-TiO2/LNT/CH3NH3PbBr3/Spiro-OMeTAD/Ag with leaves and needles like TiO2 electron collector, exhibit high efficiency up to 9% being supported by high open-circuit voltage and fill factor up to 0.8 V and 0.89, respectively. The second Perovskite Solar Cell structure FTO/Compact-TiO2/Meso-porous TiO2/CH3NH3PbBr3/Spiro-OMeTAD/Ag with meso-porous TiO2 electron collector, efficiency is 6.2% with open-circuit voltage and fill factor up to 0.77 V and 0.71 respectively. As compared to meso-porous TiO2 electron collector layer, leaves and needles like TiO2 has better electron band alignment with compact TiO2 as hole blocking layer and hence, results in higher efficiency.
Guojia Fang - One of the best experts on this subject based on the ideXlab platform.
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Perovskite Solar Cell based on network nanoporous layer consisted of tio2 nanowires and its interface optimization
Journal of Power Sources, 2015Co-Authors: Hong Tao, Jing Wang, Qin Liu, Jiawei Wan, Guang Yang, Guojia FangAbstract:Abstract Anatase TiO2 film with 3D network nanoporous structure consisted of 1D nanowires is obtained on SnO2:F (FTO) glass substrate by in-situ hydrothermal synthesis and applied in mesoporous Perovskite (CH3NH3PbI3) Solar Cell. A thin Ti film is deposited on FTO substrate by magnetron sputtering before the hydrothermal treatment with sodium hydroxide solution. Then, a layer of network nanoporous TiO2 (NT) film is formed. The efficiency of Perovskite Solar Cell based on this 3D structure with one-step sintering can be optimized to 9.19%. The NT film consisted of 1D TiO2 nanowires is beneficial to the transmission of charge carriers and the infiltration of hole transport material. And this one-step sintering process can reduce the interface defects and enhance the fill factor of the device. Then, we further optimize the surface of NT layer through TiCl4 post-treatment. The post-treatment can optimize the carrier separation and the deposition of Perovskite layer, thus improving the open-circuit voltage (Voc) and short-circuit current density (Jsc) of Perovskite Solar Cell. As a result, the value of Jsc gets an enhancement of 45.63% and the efficiency of Perovskite Solar Cell reaches up to 12.78%.
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Perovskite Solar Cell with an efficient tio2 compact film
ACS Applied Materials & Interfaces, 2014Co-Authors: Weijun Ke, Guojia Fang, Jing Wang, Xingzhong ZhaoAbstract:A Perovskite Solar Cell with a thin TiO2 compact film prepared by thermal oxidation of sputtered Ti film achieved a high efficiency of 15.07%. The thin TiO2 film prepared by thermal oxidation is very dense and inhibits the recombination process at the interface. The optimum thickness of the TiO2 compact film prepared by thermal oxidation is thinner than that prepared by spin-coating method. Also, the TiO2 compact film and the TiO2 porous film can be sintered at the same time. This one-step sintering process leads to a lower dark current density, a lower series resistance, and a higher recombination resistance than those of two-step sintering. Therefore, the Perovskite Solar Cell with the TiO2 compact film prepared by thermal oxidation has a higher short-circuit current density and a higher fill factor.
Xixi Jiang - One of the best experts on this subject based on the ideXlab platform.
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Efficient Compact-Layer-Free, Hole-Conductor-Free, Fully Printable Mesoscopic Perovskite Solar Cell
The journal of physical chemistry letters, 2016Co-Authors: Xixi Jiang, Yuli Xiong, Yaoguang Rong, Anyi Mei, Li Hong, Yingxia Jin, Qingju Liu, Hongwei HanAbstract:A compact-layer-free, hole-conductor-free, fully printable mesoscopic Perovskite Solar Cell presents a power conversion efficiency of over 13%, which is comparable to that of the device with a TiO2 compact layer. The different wettability of the Perovskite precursor solution on the surface of FTO and TiO2 possesses a significant effect on realizing efficient mesoscopic Perovskite Solar Cell. This result shows a promising future in printable Solar Cells by further simplifying the fabrication process and lowering the preparation costs.