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    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... 

    Plasmonic effects of infiltrated silver nanoparticles inside TiO2 film: Enhanced photovoltaic performance in DSSCs

    , Article Journal of the American Ceramic Society ; Volume 99, Issue 1 , 2016 , Pages 167-173 ; 00027820 (ISSN) Andaji Garmaroudi, Z ; Mohammadi, M. R ; Sharif University of Technology
    Blackwell Publishing Inc 
    The plasmonic effects of infiltrated silver (Ag) nanoparticles, with different contents, inside a nanostructured TiO2 film on the photovoltaic performance of dye-sensitized solar cells (DSSCs) are explored. The synthesized Ag nanoparticles are immobilized onto deposited TiO2 nanoparticles by a new strategy using 3-mercaptopropionic acid (MPA), a bifunctional linker molecule. Transmission electron microscope (TEM) images show that monodispersed Ag and polydispersed TiO2 nanoparticles have an average diameter of 12 ± 3 nm and 5 ± 1 nm, respectively. Moreover, Fourier transform infrared spectroscopy (FTIR) analysis reveals that Ag nanoparticles were successfully functionalized and capped with... 

    Surface engineering of pbs colloidal quantum dots using atomic passivation for photovoltaic applications

    , Article 8th International Conference on Materials for Advanced Technologies, 28 June 2015 through 3 July 2015 ; Volume 139 , 2016 , Pages 117-122 ; 18777058 (ISSN) Tavakoli, M. M ; Sharif University of Technology
    Elsevier Ltd 
    Solution-processed quantum dots (QDs) have attracted significant attention for the low-cost fabrication of optoelectronic devices. Here, we synthesized PbS QDs via hot injection method and passivated the trap states by using short thiols and dopant elements for photovoltaic application. In order to study the effect of dopants on photovoltaic application, PbS QDs were doped by using three different cations: Cadmium, Calcium, and Zinc. We utilized Time resolvel Photoluminescence measurement to study the carriers lifetime for different samples and found that the carriers life time increases ∼80% by using Cd as a dopant compared with undoped sample. In addition, the results of J-V measurement... 

    A facile low temperature route to deposit a TiO2 scattering layer for efficient dye-sensitized solar cells

    , Article RSC Advances ; Volume 6, Issue 75 , 2016 , Pages 70895-70901 ; 20462069 (ISSN) Andaji Garmaroudi, Z ; Abdi Jalebi, M ; Mohammadi, M. R ; Friend, R. H ; Sharif University of Technology
    Royal Society of Chemistry  2016
    Herein, we demonstrate a facile low temperature chemical bath deposition approach to deposit a light scattering layer on a nanostructured mesoporous TiO2 bottom layer in a dye-sensitized solar cell architecture. Large TiO2 nanoparticles were formed on the top surface of photoanode electrodes via hydrolysis of TiCl4 at 70 °C. We controlled the size and agglomeration of these TiO2 nanoparticles by altering the concentration of TiCl4 in the chemical bath during the hydrolysis process. Electron microscope images revealed that mono-dispersed scattering particles having uneven surfaces with diameters between 100 to 300 nm formed on the mesoporous titania layer. The scattering behavior of the... 

    Part load behavior of molten salt cavity receiver solar tower plants under storage mode operational mode

    , Article ASME 2016 10th International Conference on Energy Sustainability, ES 2016, collocated with the ASME 2016 Power Conference and the ASME 2016 14th International Conference on Fuel Cell Science, Engineering and Technology, 26 June 2016 through 30 June 2016 ; Volume 1 , 2016 ; 9780791850220 (ISBN) Mostafavi Tehrani, S. S ; Shafiei Ghazani, A ; Taylor, R. A ; Saberi, P ; Sharif University of Technology
    American Society of Mechanical Engineers  2016
    The performance of the tower based concentrated solar thermal (CST-tower) plant is very sensitive to the operation strategy of the plant and the incident heat flux on the receiver. To date, most studies have been examined only the design mode characteristics of the cavity receivers, but this paper significantly expands the literature by considering non-design operating conditions of this important sub-component of the CST-tower plants. A feasible non-design operating conditions of the cavity receivers that was considered in this study is the storage mode of operation. Two practical dynamic control strategies were examined then to find the most efficient approach: fixed solar field mass... 

    Broadband and low-loss plasmonic Light trapping in dye-sensitized solar cells using micrometer-scale rodlike and spherical core-shell plasmonic particles

    , Article ACS Applied Materials and Interfaces ; Volume 8, Issue 25 , 2016 , Pages 16359-16367 ; 19448244 (ISSN) Malekshahi Byranvand, M ; Nemati Kharat, A ; Taghavinia, N ; Dabirian, A ; Sharif University of Technology
    American Chemical Society  2016
    Dielectric scattering particles have widely been used as embedded scattering elements in dye-sensitized solar cells (DSCs) to improve the optical absorption of the device. Here we systematically study rodlike and spherical core-shell silica@Ag particles as more effective alternatives to the dielectric scattering particles. The wavelength-scale silica@Ag particles with sufficiently thin Ag shell support hybrid plasmonic-photonic resonance modes that have low parasitic absorption losses and a broadband optical response. Both of these features lead to their successful deployment in light trapping in high-efficiency DSCs. Optimized rodlike silica@Ag@silica particles improve the power conversion... 

    Optimization of photovoltaic electrolyzer hybrid systems; taking into account the effect of climate conditions

    , Article Energy Conversion and Management ; Volume 118 , 2016 , Pages 438-449 ; 01968904 (ISSN) Sayedin, F ; Maroufmashat, A ; Sattari, S ; Elkamel, A ; Fowler, M ; Sharif University of Technology
    Elsevier Ltd  2016
    Solar energy will make a valuable contribution for power generation in the future. However the intermittency of solar energy has become an important issue in the utilization of PV system, especially small scale distributed solar energy conversion systems. The issue can be addressed through the management of production and storage of the energy in the form of hydrogen. The hydrogen can be produced by solar photovoltaic (PV) powered electrolysis of water. The amount of transferred energy to an electrolyzer from a PV module is a function of the distance between maximum power points (MPP) of PV module and the electrolyzer operating points. The distance can be minimized by optimizing the number... 

    Selecting Support Layer for Electrodeposited Efficient Cobalt Oxide/Hydroxide Nanoflakes to Split Water

    , Article ACS Sustainable Chemistry and Engineering ; Volume 4, Issue 6 , 2016 , Pages 3151-3159 ; 21680485 (ISSN) Naseri, N ; Esfandiar, A ; Qorbani, M ; Moshfegh, A. Z ; Sharif University of Technology
    American Chemical Society  2016
    Energy and environment crises motivated scientists to develop sustainable, renewable, and clean energy resources mainly based on solar hydrogen. For this purpose, one main challenge is the low cost flexible substrates for designing earth abundant efficient cocatalysts to reduce required water oxidation overpotential. Here, a systematic morphological and electrochemical study has been reported for cobalt oxide/hydroxide nanoflakes simply electrodeposited on four different commercially available substrates, titanium, copper sheet, steel mesh, and nickel foam. Remarkable dependence between the used substrate, morphology, and electrocatalytic properties of nanoflakes introduced flexible porous... 

    Efficient dye-sensitized solar cells based on TiO2 nanoparticles and skein-like nanotubes: effect of arrangement modes of the layers and TiCl4 treatment

    , Article Journal of the Taiwan Institute of Chemical Engineers ; Volume 61 , 2016 , Pages 138-146 ; 18761070 (ISSN) Mojaddami, M ; Andaji Garmaroudi, Z ; Mohammadi, M. R ; Madaah Hosseini, H. R ; Sharif University of Technology
    Herein, we report a double-layer photoanode electrode composed of TiO2 nanoparticles active layer and a mixture of nanoparticles and newly proposed skein-like nanotubes (NTs) top layer. Such structure performs well in solar light harvesting due to first, the top layer exhibits superior light scattering and second, the active layer with high dye-loading can make better use of the back-scattered light. The results reveal that 30-40 nm nanoparticles have anatase structure, whereas 5-7 μm skein-like NTs show a mixture of anatase and rutile phases. Photovoltaic measurements demonstrate that by tuning mass ratio between nanoparticles and skein-like NTs, the cells based on single-layer photoanode... 

    Improving transparency in dye-sensitized nanostructured solar cells by optimizing nano-porous titanium dioxide photo-electrode

    , Article Journal of Materials Science: Materials in Electronics ; Volume 28, Issue 11 , 2017 , Pages 7811-7818 ; 09574522 (ISSN) Nikfarjam, A ; Mohammadpour, R ; Kasaeian, A ; Zebhi, Z ; Sharif University of Technology
    Springer New York LLC  2017
    Today’s the technology based on dye-sensitized solar cells (DSSCs) has an important role in all photovoltaic system technologies. DSSCs can generate electricity with various degrees of transparency; this makes it suitable for use in various industries, especially in construction industry as smart windows. In fact DSSC can produce electricity and having natural light, simultaneously. It is obvious that DSSCs need to absorb solar radiation as much as possible. Since, the effective use of all incident lights leads to an increase in cell efficiency and this increase in efficiency is related to the amount of dye adsorbed on the surface of nanostructured electrode, so higher amount of dye for... 

    Nonlinear adaptive control of grid-connected three-phase inverters for renewable energy applications

    , Article International Journal of Control ; Volume 90, Issue 1 , 2017 , Pages 53-67 ; 00207179 (ISSN) Mahdian Dehkordi, N ; Namvar, M ; Karimi, H ; Piya, P ; Karimi Ghartemani, M ; Sharif University of Technology
    Distributed generation (DG) units are often interfaced to the main grid using power electronic converters including voltage-source converters (VSCs). A VSC offers dc/ac power conversion, high controllability, and fast dynamic response. Because of nonlinearities, uncertainties, and system parameters’ changes involved in the nature of a grid-connected renewable DG system, conventional linear control methods cannot completely and efficiently address all control objectives. In this paper, a nonlinear adaptive control scheme based on adaptive backstepping strategy is presented to control the operation of a grid-connected renewable DG unit. As compared to the popular vector control technique, the... 

    Experimental investigation of a solar still equipped with an external heat storage system using phase change materials and heat pipes

    , Article Desalination ; Volume 409 , 2017 , Pages 128-135 ; 00119164 (ISSN) Faegh, M ; Shafii, M. B ; Sharif University of Technology
    Elsevier B.V  2017
    In this study, a novel idea of storing the latent heat of condensing vapor in solar stills by means of phase change materials (PCMs) as a thermal storage is experimentally investigated. During the daytime, the generated water vapor by the solar energy, is conducted to an external condenser filled with PCM to be condensed. The wasted latent heat is absorbed by PCM and thereby stored. It is worth noting that there is no direct contact between the saline water and the PCM, therefore, the solar energy is not directly stored in the PCM. In the evening, the energy stored in the PCM is transferred as heat to the saline water by heat pipes and enables the desalination process to continue. Several... 

    Practical battery size optimization of a PV system by considering individual customer damage function

    , Article Renewable and Sustainable Energy Reviews ; Volume 67 , 2017 , Pages 36-50 ; 13640321 (ISSN) Mehrabankhomartash, M ; Rayati, M ; Sheikhi, A ; Ranjbar, A. M ; Sharif University of Technology
    Today, energy crises attracted many researchers’ attention to renewable energy technologies especially photovoltaic (PV) systems. The main challenge of PV systems is unpredictable nature of solar power generation. To overcome this challenge, a storage system is integrated which reduces demand reliance on electricity grid and uses excess energy that solar panels produce. As investment cost of the storage system is considerable, finding an optimal technology, size, and configuration are crucial. In this paper, the optimal battery system is excluded from existing PV plant installing in a commercial building located in Mashhad/Iran. Here, the sizing procedure is based on a financial evaluation... 

    Low-temperature solution-based processing to 7.24% efficient superstrate CuInS2 solar cells

    , Article Solar Energy ; Volume 157 , 2017 , Pages 581-586 ; 0038092X (ISSN) Cheshme Khavar, A.H ; Mahjoub, A. R ; Taghavinia, N ; Sharif University of Technology
    Elsevier Ltd  2017
    The fabrication of high performance, solution-processed CIGS family solar cells is based on high-temperature crystallization processes in chalcogen-containing atmosphere and/or using dangerous solvents like hydrazine. The non-hydrazine sulfurization- and selenization-free reports typically suffer from poor grain structures. We report a facile strategy to overcome grain growth limitations at very low temperature processing (250 °C). Selenium free Superstrate configuration CuInS2 (CIS) solar cells are fabricated using a nanocrystals ink which avoiding from high temperature selenization or/and sulfurization is targeted. We investigated the effect of intentional M doping (M = Sb, Zn, Cd and Sn)... 

    Microstructure, morphology and electrochemical properties of Co nanoflake water oxidation electrocatalyst at micro- and nanoscale

    , Article RSC Advances ; Volume 7, Issue 21 , 2017 , Pages 12923-12930 ; 20462069 (ISSN) Naseri, N ; Solaymani, S ; Ghaderi, A ; Bramowicz, M ; Kulesza, S ; Ţălu, Ş ; Pourreza, M ; Ghasemi, S ; Sharif University of Technology
    Royal Society of Chemistry  2017
    Nowadays, fossil fuel limitations and environmental concerns push researchers to find clean and renewable energy resources. Solar hydrogen production via water splitting reactions in electrochemical and/or photo-electrochemical systems has been accepted as a promising route and efficient electrocatalysts are involved in both. Here, cobalt nanoflakes with an oxide/hydroxide surface and a conductive metallic core are grown on commercially available steel mesh modified with carbon based nanocomposites as a support layer. The portion of reduced graphene oxide sheets was changed from 0 to 100 wt% and the correlation of this concentration with the surface morphology and electro-catalytic activity... 

    Resolving a critical instability in perovskite solar cells by designing a scalable and printable carbon based electrode-interface architecture

    , Article Advanced Energy Materials ; Volume 8, Issue 31 , 2018 ; 16146832 (ISSN) Mashhoun, S ; Hou, Y ; Chen, H ; Tajabadi, F ; Taghavinia, N ; Egelhaaf, H. J ; Brabec, C. J ; Sharif University of Technology
    Wiley-VCH Verlag  2018
    Thin-film solar cells based on hybrid organo-halide lead perovskites achieve over 22% power conversion efficiency (PCE). A photovoltaic technology at such high performance is no longer limited by efficiency. Instead, lifetime and reliability become the decisive criteria for commercialization. This requires a standardized and scalable architecture which does fulfill all requirements for larger area solution processing. One of the most highly demanded technologies is a low temperature and printable conductive ink to substitute evaporated metal electrodes for the top contact. Importantly, that electrode technology must have higher environmental stability than, for instance, an evaporated silver... 

    Exergy analysis of parabolic trough solar collectors using Al2O3/synthetic oil nanofluid

    , Article Solar Energy ; Volume 173 , 2018 , Pages 1236-1247 ; 0038092X (ISSN) Khakrah, H ; Shamloo, A ; Kazemzadeh Hannani, S ; Sharif University of Technology
    Elsevier Ltd  2018
    Parabolic trough solar collector (PTC) is one of the most mature and widely used type of solar energy harnessing devices. Therefore, investigation of the effect of various operational conditions on the overall efficiency of these devices has been topic of substantial interest in the recent decade. Moreover, utilization of nanoparticles as a useful additive to the working fluid should be examined thoroughly to optimize the collector's outputs. To do so, in the present study, energy and exergy efficiencies of a typical PTC as a function of several involving parameters are numerically calculated. These parameters are nanoparticle volume fraction (from 0 to 5 percent), environment wind speed... 

    A review on pulsating heat pipes: from solar to cryogenic applications

    , Article Applied Energy ; Volume 222 , 15 July , 2018 , Pages 475-484 ; 03062619 (ISSN) Alhuyi Nazari, M ; Ahmadi, M. H ; Ghasempour, R ; Behshad Shafii, M ; Mahian, O ; Kalogirou, S ; Wongwises, S ; Sharif University of Technology
    Elsevier Ltd  2018
    Pulsating heat pipes (PHPs) are compact cooling equipment used for various applications. This type of heat pipes can be used in renewable energy systems, cooling electronic devices, heat recovery systems and many other applications. Since PHPs have superior thermal performance, by applying them in energy systems enhance their efficiency. In addition, PHPs are a reliable medium for cooling various devices which have high heat flux. In this study, various works conducted on the applications of PHPs are reviewed and analyzed. It is concluded that PHPs are efficient and reliable devices for utilization in various energy systems. Moreover, at very low temperatures, such as cryogenic applications,... 

    Greener, nonhalogenated solvent systems for highly efficient Perovskite solar cells

    , Article Advanced Energy Materials ; Volume 8, Issue 21 , 25 July , 2018 ; 16146832 (ISSN) Yavari, M ; Mazloum Ardakani, M ; Gholipour, S ; Tavakoli, M. M ; Turren Cruz, S. H ; Taghavinia, N ; Gratzel, M ; Hagfeldt, A ; Saliba, M ; Sharif University of Technology
    Wiley-VCH Verlag  2018
    All current highest efficiency perovskite solar cells (PSCs) use highly toxic, halogenated solvents, such as chlorobenzene (CB) or toluene (TLN), in an antisolvent step or as solvent for the hole transporter material (HTM). A more environmentally friendly antisolvent is highly desirable for decreasing chronic health risk. Here, the efficacy of anisole (ANS), as a greener antisolvent for highest efficiency PSCs, is investigated. The fabrication inside and outside of the glovebox showing high power conversion efficiencies of 19.9% and 15.5%, respectively. Importantly, a fully nonhalogenated solvent system is demonstrated where ANS is used as both the antisolvent and the solvent for the HTM.... 

    Analytical study of electro-elastic fields in quantum nanostructure solar cells: the inter-nanostructure couplings and geometrical effects

    , Article Acta Mechanica ; Volume 229, Issue 7 , 2018 , Pages 3089-3106 ; 00015970 (ISSN) Rashidinejad, E ; Naderi, A. A ; Sharif University of Technology
    Springer-Verlag Wien  2018
    Recent investigations on multifunctional piezoelectric semiconductors have shown their excellent potential as photovoltaic components in high-efficiency third-generation quantum nanostructure (QNS) solar cells. The current work is devoted to studying the electro-elastic behavior of high-density QNS photovoltaic semiconductors within which initial mismatch strains of arrays of quantum dots (QDs) or quantum wires (QWRs) induce coupled electro-mechanical fields. The inter-nanostructure couplings which are of great importance in high-density QNS arrays are incorporated in the presented analytical framework. In practice, QNSs with different geometries such as spherical, cuboidal, or pyramidal QDs...