Search for: open-circuit-voltage
0.006 seconds
Total 42 records

    Improving the performance of planar perovskite solar cell using NH4Cl treatment of SnO2 as electron transport layer

    , Article Surfaces and Interfaces ; 2021 ; 24680230 (ISSN) Keshtmand, R ; Zamani Meymian, M. R ; Taghavinia, N ; Sharif University of Technology
    Elsevier B.V  2021
    Here in this research, a modified interface between the electron transport layer (ETL) and the perovskite layer in a perovskite solar cell (PSC) is provided by adding the ammonium chloride (NH4Cl) to the tin oxide (SnO2) as the modified ETL of a planar structure as follows: fluorine-doped tin oxide (FTO)/NH4Cl-SnO2/Mixed cation perovskite/Copper indium disulfide (CIS)/Gold (Au). The effects of NH4Cl on ETL are investigated in different amounts from 0.003 to 0.02 M and the best results were obtained in the amount of 0.013 M. The best NH4Cl-SnO2 ETL could increase the power conversion efficiency (PCE) of fabricated planar PSC by 16.79% with open-circuit voltage (Voc) of 1.15 V and negligible... 

    Influence of perovskite morphology on slow and fast charge transport and hysteresis in the perovskite solar cells

    , Article Journal of Physical Chemistry Letters ; Volume 7, Issue 22 , 2016 , Pages 4614-4621 ; 19487185 (ISSN) Mohammadian, N ; Moshaii, A ; Alizadeh, A ; Gharibzadeh, S ; Mohammadpour, R ; Sharif University of Technology
    American Chemical Society  2016
    We have investigated the influence of perovskite morphology on slow and fast charge transport in the perovskite solar cells. Solar cells with different perovskite cuboid sizes (50-300 nm) have been fabricated using various methylammonium iodide concentrations. Both the low-frequency capacitance and hysteresis are maximum for the cell with the largest perovskite grains (300 nm). The low-frequency capacitance is about three orders of magnitude greater than the intermediate frequency capacitance, indicating the great role of ions on the slow responses and hysteresis. The measurement of open-circuit voltage decay indicates that for the large grains of 300 nm up to 70% of Voc remains across the... 

    Interfacial investigation on printable carbon-based mesoscopic perovskite solar cells with niox/c back electrode

    , Article ACS Applied Materials and Interfaces ; Volume 9, Issue 30 , 2017 , Pages 25204-25215 ; 19448244 (ISSN) Behrouznejad, F ; Tsai, C. M ; Narra, S ; Diau, E. W. G ; Taghavinia, N ; Sharif University of Technology
    American Chemical Society  2017
    Solar cells with high efficiency, low cost, and high stability are the target for the new generation of solar cells. A fully printable perovskite (CH3NH3PbI3) solar cell (PSC) with device architecture FTO/TiO2/Al2O3/NiOx/C is fabricated in the current research as a low-cost and relatively stable structure and is investigated to determine how different fabrication factors such as the thickness of the insulating spacer layer (Al2O3) or treatments such as heat and UV-O3 treatments can affect the interfacial properties of this multilayer mesoporous structure. X-ray photoelectron spectra (XPS) show that UV-O3 treatment increases the Ni3+(Ni2O3) phase on the surface of the black nickel oxide layer... 

    Ab initio study of electronic effects in the ZnO/TiO2 core/shell interface: Application in dye sensitized solar cells

    , Article RSC Advances ; Vol. 4, issue. 1 , April , 2014 , p. 301-307 Pazoki, M ; Nafari, N ; Taghavinia, N ; Sharif University of Technology
    Core/shell structure of ZnO nanowires coated with a monolayer of TiO 2 is investigated using Density Functional Theory (DFT). The electronic states of the semiconductor is calculated and compared before and after coating of the TiO2 monolayer on a ZnO [101 0] surface. The effect of TiO2 coating induce surface states changes and shifts the conduction and valence band edges to higher energies. Our results, in qualitative agreement with the experimental work of Matt Law et al. (J. Phys. Chem. B, 110, 22652), show an increase in open circuit voltage and a decrease in short circuit current in ZnO/TiO2 core shell dye sensitized solar cells. Regarding the semiconductor density of states (DOS), TiO2... 

    Control of gas metal arc welding by an extended DMC

    , Article Proceedings of the IEEE International Conference on Control Applications ; 2012 , Pages 1430-1434 ; 9781467345033 (ISBN) Sartipizadeh, H ; Haeri, M ; Sharif University of Technology
    Efficient control of gas metal arc welding process enables us to have high quality products in consequence of achieving high quality weld. In this paper, an extended dynamic matrix controller is designed and applied on the gas metal arc welding process, which is considered as a nonlinear multi-inputs multi-outputs system. In order to reach a high quality weld, the outputs, welding current and arc length, are effectively controlled by open circuit voltage and wire feed speed. The structure and performance of the proposed controller are discussed in detail, and then a set of simulation results is presented to verify its efficiencies  

    Efficient nanostructured biophotovoltaic cell based on bacteriorhodopsin as biophotosensitizer

    , Article ACS Sustainable Chemistry and Engineering ; Volume 3, Issue 5 , March , 2015 , Pages 809-813 ; 21680485 (ISSN) Mohammadpour, R ; Janfaza, S ; Sharif University of Technology
    American Chemical Society  2015
    Here, we report on utilizing a photoactive protein, bacteriorhodopsin (bR), as a light harvester in combination with TiO2 nanoparticles in biosensitized solar cell application. Experiments have been conducted to investigate the capability of surface adsorption of bR on nanoparticular TiO2photoanodes. Different pretreatment processes have been done to modify the interface of TiO2 nanoparticles and bR as a biophotosensitizer. Our results indicate the feasibility of efficient immobilization and photoinduced charge transfer of bR to the nanostructured TiO2 photoelectrode. Under illumination of simulated AM1.5 sunlight, the solar-light-to-electricity... 

    Effect of crystallinity and morphology of TiO2 nano-structures on TiO2:P3HT hybrid photovoltaic solar cells

    , Article Applied Solar Energy (English translation of Geliotekhnika) ; Volume 51, Issue 1 , January , 2015 , Pages 34-40 ; 0003701X (ISSN) Boroomandnia, A ; Kasaeian, A. B ; Nikfarjam, A ; Akbarzadeh, A ; Mohammadpour, R ; Sharif University of Technology
    Allerton Press Incorporation  2015
    A comparative study has been made of hybrid solar cells based on poly(3-hexylthiophene) (P3HT) and different nano-structures of TiO2. Electrospinning, which is a low cost production method for large area nanofibrous films, was employed to fabricate TiO2 nanofibers and spin coating method was employed to fabricate organic-inorganic hybrid solar cells based on P3HT and TiO2 nanostructures. The performance of the hybrid solar cells was analyzed for four density levels of the TiO2 nanostructure. It was found that higher densities of TiO2 leads to more interface area and generates excitons, so that the power conversion efficiency increases to... 

    An analytical-numerical approach for parameter determination of a five-parameter single-diode model of photovoltaic cells and modules

    , Article International Journal of Sustainable Energy ; Volume 35, Issue 4 , 2016 , Pages 396-410 ; 14786451 (ISSN) Hejri, M ; Mokhtari, H ; Azizian, M. R ; Söder, L ; Sharif University of Technology
    Taylor and Francis Ltd  2016
    Parameter extraction of the five-parameter single-diode model of solar cells and modules from experimental data is a challenging problem. These parameters are evaluated from a set of nonlinear equations that cannot be solved analytically. On the other hand, a numerical solution of such equations needs a suitable initial guess to converge to a solution. This paper presents a new set of approximate analytical solutions for the parameters of a five-parameter single-diode model of photovoltaic (PV) cells and modules. The proposed solutions provide a good initial point which guarantees numerical analysis convergence. The proposed technique needs only a few data from the PV current-voltage... 

    Globularity-selected large molecules for a new generation of multication perovskites

    , Article Advanced Materials ; Volume 29, Issue 38 , 2017 ; 09359648 (ISSN) Gholipour, S ; Ali, A. M ; Correa Baena, J. P ; Turren Cruz, S. H ; Tajabadi, F ; Tress, W ; Taghavinia, N ; Grätzel, M ; Abate, A ; De Angelis, F ; Gaggioli, C. A ; Mosconi, E ; Hagfeldt, A ; Saliba, M ; Sharif University of Technology
    Perovskite solar cells (PSCs) use perovskites with an APbX3 structure, where A is a monovalent cation and X is a halide such as Cl, Br, and/or I. Currently, the cations for high-efficiency PSCs are Rb, Cs, methylammonium (MA), and/or formamidinium (FA). Molecules larger than FA, such as ethylammonium (EA), guanidinium (GA), and imidazolium (IA), are usually incompatible with photoactive “black”-phase perovskites. Here, novel molecular descriptors for larger molecular cations are introduced using a “globularity factor”, i.e., the discrepancy of the molecular shape and an ideal sphere. These cationic radii differ significantly from previous reports, showing that especially ethylammonium (EA)... 

    Synthesis and characterization of new triphenylamine-based dyes with novel anchoring groups for dye-sensitized solar cell applications

    , Article Journal of Materials Science: Materials in Electronics ; Volume 28, Issue 2 , 2017 , Pages 1859-1868 ; 09574522 (ISSN) Salimi Beni, A ; Hosseinzadeh, B ; Azari, M ; Ghahary, R ; Sharif University of Technology
    Springer New York LLC  2017
    Three new chromophores based on the triphenylamine (MM, DM, DN) with various novel electron withdrawing anchoring groups have been synthesized for use in dye-sensitized solar cells (DSSCs). The sensitizers were characterized by 1H and 13C NMR, Mass, UV–Vis, and electrochemical analysis. The HOMO and LUMO electron distributions of the sensitizers were calculated using density functional theory on a B3LYP level for geometry optimization. The DSSC device based on DM dye showed the best photovoltaic performance among MM and DN dyes: maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 98 %, short circuit current (JSC) of 4.58 mA/cm2, open circuit voltage (VOC) of... 

    Elucidation of charge recombination and accumulation mechanism in mixed perovskite solar cells

    , Article Journal of Physical Chemistry C ; Volume 122, Issue 27 , 2018 , Pages 15149-15154 ; 19327447 (ISSN) Yadav, P ; Turren Cruz, S. H ; Prochowicz, D ; Tavakoli, M. M ; Pandey, K ; Zakeeruddin, S. M ; Gratzel, M ; Hagfeldt, A ; Saliba, M ; Sharif University of Technology
    American Chemical Society  2018
    Organic-inorganic perovskite solar cells (PSCs) have gained considerable attention owing to their impressive photovoltaic properties and simple device manufacturing. In general, PSC employs a perovskite absorber material sandwiched between an electron and hole selective transport layer optimized with respect to optimal band alignment, efficient charge collection, and low interfacial recombination. The interfaces between the perovskite absorber and respective selective contacts play a crucial role in determining photovoltaic performance and stability of PSCs. However, a fundamental understanding is lacking, and there is poor understanding in controlling the physical processes at the... 

    New organic dyes with diphenylamine core for dye-sensitized solar cells

    , Article Journal of Materials Science: Materials in Electronics ; Volume 29, Issue 8 , April , 2018 , Pages 6323-6336 ; 09574522 (ISSN) Salimi Beni, A. R ; Karami, M ; Hosseinzadeh, B ; Ghahary, R ; Sharif University of Technology
    Springer New York LLC  2018
    In the current investigation, four novel donoracceptor type organic dyes including (DPA-Ba, DPA-Hy, DPA-Rh, DPA-Cy), are proposed and their photophysical and electrochemical properties as well as dye-sensitized solar cell performance are systematically investigated. Among these dyes diphenylamine is utilized as an-electron donor while barbituric acid, hydantoin, rhodanine-n-acetic acid and cyano acetic acid, are proposed as anchoring groups as dye-sensitized solar cells (DSSCs). The synthesized dyes are characterized using FT-IR, NMR, mass spectrometry, absorbance and electrochemical measurements. The photophysical, electrochemical and photovoltaic properties of the solar cells based on... 

    Surface treatment of perovskite layer with guanidinium iodide leads to enhanced moisture stability and improved efficiency of perovskite solar cells

    , Article Advanced Materials Interfaces ; Volume 7, Issue 14 , 2020 Chavan, R. D ; Prochowicz, D ; Tavakoli, M. M ; Yadav, P ; Hong, C. K ; Sharif University of Technology
    Wiley-VCH Verlag  2020
    Interfacial engineering between the perovskite and hole transport layers has emerged as an effective way to improve perovskite solar cell (PSC) performance. A variety of organic halide salts are developed to passivate the traps and enhance the charge carrier transport. Here, the use of guanidinium iodide (GuaI) for interfacial modification of mixed-cation (Cs)x(FA)1−xPbI3 perovskite films, which results in the formation of a low-dimensional δ-FAPbI3-like phase on the 3D perovskite surface, is reported. The presence of this thin layer facilitates charge transfer at interfaces and reduces charge carrier recombination pathways as evidenced by enhanced carrier lifetimes and favorable interfacial... 

    Efficient bio-nano hybrid solar cells via purple membrane as sensitizer

    , Article BioNanoScience ; Vol. 4, issue. 1 , 2014 , pp. 71-77 ; ISSN: 21911630 Janfaza, S ; Molaeirad, A ; Mohamadpour, R ; Khayati, M ; Mehrvand, J ; Sharif University of Technology
    Bacteriorhodopsin is a heptahelical protein found in the purple membrane of Halobacterium salinarum. The performance of bacteriorhodopsin was evaluated as a sensitizer in dye-sensitized solar cells (DSSCs). Bacteriorhodopsin was efficiently immobilized on the titanium dioxide nanoparticles and then tested for its ability to convert solar radiation to electricity. The photovoltaic performance of DSSC based on the bacteriorhodopsin sensitizer has been examined. Under AM1.5 irradiation, a short-circuit current of 0.28 mA cm−2, open-circuit voltages of 0.51 V, fill factor of 0.62, and an overall energy conversion efficiency of 0.09 % are achieved employing platinum as a counter electrode. Carbon... 

    On the parameter extraction of a five-parameter double-diode model of photovoltaic cells and modules

    , Article IEEE Journal of Photovoltaics ; Vol. 4, issue. 3 , 2014 , pp. 915-923 ; ISSN: 21563381 Hejri, M ; Mokhtari, H ; Azizian, M. R ; Ghandhari, M ; Soder, L ; Sharif University of Technology
    The main contribution of this paper is to present a new set of approximate analytical solutions for the parameters of a photovoltaic (PV) five-parameter double-diode model that can be used as initial values for the numerical solutions based on the Newton-Raphson method. The proposed formulations are developed based on only the limited information given by the PV manufacturers, i.e., the open-circuit voltage (V), the short circuit current (I), and the current and voltage at the maximum power point (Im). Compared with the existing techniques that require the entire experimental I-V curve or additional information such as the slope of the I-V curves of the open circuit and the short circuit... 

    Controlling electron injection and electron transport of dye-sensitized solar cells aided by incorporating CNTs into a Cr-doped TiO2 photoanode

    , Article Electrochimica Acta ; Volume 111 , 2013 , Pages 921-929 ; 00134686 (ISSN) Massihi, N ; Mohammadi, M. R ; Bakhshayesh, A. M ; Abdi Jalebi, M ; Sharif University of Technology
    In the present work, we focused on simultaneously control electron injection and electron transport, in dye-sensitized solar cells (DSSCs), aided by introducing Cr3+ and CNTs into a TiO2 photoanode, respectively. X-ray photoelectron spectroscopy (XPS) revealed that, Cr 3+ and CNTs were successfully incorporated into the TiO2 lattice without forming secondary phases. X-ray diffraction (XRD) analysis showed that Cr introduction has perfectly balanced the amount of anatase and rutile phases in order to accomplish a more efficient cell. Field emission scanning electron microscope (FE-SEM) images showed deposited films to have a porous morphology composed of nanoparticles and TiO2 nanoparticles... 

    Improved efficiency of dye-sensitized solar cells by design of a proper double layer photoanode electrodes composed of Cr-doped TiO2 transparent and light scattering layers

    , Article Journal of Sol-Gel Science and Technology ; Volume 67, Issue 1 , 2013 , Pages 77-87 ; 09280707 (ISSN) Mohammadi, M. R ; Bakhshayesh, A. M ; Sadri, F ; Masroor, M ; Sharif University of Technology
    A new strategy for enhancing the efficiency of TiO2 dye-sensitized solar cells (DSSCs) by design of a new double layer film doped with Cr ions, with various morphologies, is reported. X-ray diffraction and field emission scanning electron microscope (FE-SEM) analyses revealed that the synthesized nanoparticles had uniform and nanometer grains with different phase compositions and average crystallite size in the range of 10-12 nm depending upon Cr atomic percentage. UV-vis absorption showed that Cr introduction enhanced the visible light absorption of TiO2 nanoparticles by shifting the absorption onset to visible light region. Furthermore, the band gap energy of nanoparticles decreased with... 

    A simple low pressure method for the synthesis of TiO2 nanotubes and nanofibers and their application in DSSCs

    , Article Electronic Materials Letters ; Volume 11, Issue 4 , July , 2015 , Pages 625-632 ; 17388090 (ISSN) Karimipour, M ; Mashhoun, S ; Mollaei, M ; Molaei, M ; Taghavinia, N ; Sharif University of Technology
    Kluwer Academic Publishers  2015
    TiO2 nanotubes were synthesized using a modified autoclave-free thermal method from as-prepared initial powders. The size of initial powders (IP) was found to be critical in determining the morphology and crystal structure of the final product. Oleylamine (OA) was used as the polymer agent in the preparation of initial powders with different mol ratios of OA/Ti: 1, 5, and 10. X-ray diffraction analysis depicted that the increase of mole ratio up to 10 resulted in smaller nanoparticles with the sizes of about 8 nm. It was also deliberated that low temperature thermally treated IP showed the characteristic diffraction pattern of titanate phase of nanotubes. Scanning electron... 

    Hydrothermal synthesis of TiO2 nanocrystals in different basic pHs and their applications in dye sensitized solar cells

    , Article Physica E: Low-Dimensional Systems and Nanostructures ; Volume 70 , June , 2015 , Pages 113-120 ; 13869477 (ISSN) Anajafi, Z ; Marandi, M ; Taghavinia, N ; Sharif University of Technology
    Elsevier  2015
    In this research TiO2 nanocrystals with sizes about 11-70 nm were grown by hydrothermal method. The process was performed in basic autoclaving pH in the range of 8.0-12.0. The synthesized anatase phase TiO2 nanocrystals were then applied in the phtoanode of the dye sensitized solar cells. It was shown that the final average size of the nanocrystals was larger when the growth was carried out in higher autoclaving pHs. The photoanodes made of TiO2 nanocrystals prepared in the pHs of 8.0 and 9.0 represented low amounts of dye adsorption and light scattering. The performance of the corresponding dye sensitized solar cells was also not acceptable. Nevertheless, the energy conversion efficiency... 

    A novel thermo-photovoltaic cell with quantum-well for high open circuit voltage

    , Article Superlattices and Microstructures ; Volume 83 , July , 2015 , Pages 61-70 ; 07496036 (ISSN) Kouhsari, E. S ; Faez, R ; Akbari Eshkalak, M ; Sharif University of Technology
    Academic Press  2015
    Abstract We design a thermo-photovoltaic Tandem cell which produces high open circuit voltage (Voc) that causes to increase efficiency (η). The currently used materials (AlAsSb-InGaSb/InAsSb) have thermo-photovoltaic (TPV) property which can be a p-n junction of a solar cell, but they have low bandgap energy which is the reason for lower open circuit voltage. In this paper, in the bottom cell of the Tandem, there is 30 quantum wells which increase absorption coefficients and quantum efficiency (QE) that causes to increase current. By increasing the current of the bottom cell, the top cell thickness must be increased because the top cell and the bottom cell should have the same current. In...