Search for: organic-inorganic
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    Effect of TiO2 nanofiber density on organic-inorganic based hybrid solar cells

    , Article International Journal of Engineering, Transactions A: Basics ; Vol. 27, issue. 7 , 2014 , p. 1133-1138 Boroumandnia, A ; Kasaeian, A. B ; Nikfarjam, A. R ; Mohammadpour, R ; Sharif University of Technology
    In this work, a comparative study of hybrid solar cells based on P3HT and TiO2 nanofibers was accomplished. Electrospinning, a low cost production method for large area nanofibrous films, was employed to fabricate the organic-inorganic hybrid solar cells based on poly (3-hexylthiophene) and TiO2 nanofibers. The performance of the hybrid solar cells was analyzed for four density levels of TiO2 nanofibers which resulted in the average power conversion efficiency of about 0.0134% under AM 1.5 simulated illuminations (100 mWcm-2). It is found that the higher densities of TiO2 lead to more interface area and generating exciton, so the power conversion efficiency will be increased till the active... 

    Vapor Assisted Solution Processing of Multi-cation Perovskites as the Absorber of Solar Cells

    , M.Sc. Thesis Sharif University of Technology Arasteh Haghdost, Mahsa (Author) ; Taghavinia, Nima (Supervisor)
    In this research, we fabricated and characterized hybrid organic-inorganic perovskite solar. The purpose of this study was the fabrication of multi-cationic perovskite films with vapor-assisted solution process, which was carried out in two different atmospheric and low-pressure conditions. In this regard, the reference cells with CH3NH3PbI3 and HC(NH2)2PbI3 compositions were made, which yielded 15.2% and 7.19% efficiencies in atmospheric conditions, and 6.38% and 2.65% in low pressure conditions, respectively. To increase the stability and to improve cell device performance, Br anion was added to the CH3NH3PbI3 structure. In optimum conditions, the conversion efficiency was 12.18%. Further... 

    Hole transport material based on modified N-annulated perylene for efficient and stable perovskite solar cells

    , Article Solar Energy ; Volume 194 , 2019 , Pages 279-285 ; 0038092X (ISSN) Sheibani, E ; Amini, M ; Heydari, M ; Ahangar, H ; Keshavarzi, R ; Zhang, J ; Mirkhani, V ; Sharif University of Technology
    Elsevier Ltd  2019
    N-annulated perylene based materials show outstanding and tunable optical and physical properties, making them suitable to be charge transport materials for optoelectronic applications. However, this type of materials has so far not been well studied in solar cells. Here, we develop a new hole transport material (HTM), namely S5, based on perylene building block terms, for organic-inorganic hybrid perovskite solar cells (PSCs). We have systematically studied the influences of the film thickness of S5 on their photovoltaic performance, and a low concentration of S5 with a thinner HTM film is favorable for obtaining higher solar cell efficiency. S5 shows excellent energy alignment with... 

    Encapsulation strategies for highly stable perovskite solar cells under severe stress testing: damp heat, freezing, and outdoor illumination conditions

    , Article ACS Applied Materials and Interfaces ; Volume 13, Issue 38 , 2021 , Pages 45455-45464 ; 19448244 (ISSN) Mohammadi, M ; Gholipour, S ; Malekshahi Byranvand, M ; Abdi, Y ; Taghavinia, N ; Saliba, M ; Sharif University of Technology
    American Chemical Society  2021
    A key direction toward managing extrinsic instabilities in perovskite solar cells (PSCs) is encapsulation. Thus, a suitable sealing layer is required for an efficient device encapsulation, preventing moisture and oxygen ingression into the perovskite layer. In this work, a solution-based, low-cost, and commercially available bilayer structure of poly(methyl methacrylate)/styrene-butadiene (PMMA/SB) is investigated for PSCs encapsulation. Encapsulated devices retained 80% of the initial power conversion efficiency (PCE) at 85 °C temperature and 85% relative humidity after 100 h, while reference devices without SB (only PMMA) suffer from rapid and intense degradation after only 2 h, under the... 

    Role of BCP layer on nonlinear properties of perovskite solar cell

    , Article Solar Energy ; Volume 213 , 2021 , Pages 383-391 ; 0038092X (ISSN) Asgary, S ; Milani Moghaddam, H ; Bahari, A ; Mohammadpour, R ; Sharif University of Technology
    Elsevier Ltd  2021
    Organic-inorganic hybrid halide perovskite materials have been most attractive for wide range of optoelectronic applications. Investigating the photo-response in these devices will be very useful to understanding cell performance in different conditions and applications. For understanding non-linearity photo-response we use the Bathocuproine (BCP) as blocking layer in two interfaces of inverted perovskite solar cell (FTO/NiO/BCP/Perovskite/PCBM/Au and FTO/NiO/Perovskite/PCBM/BCP/Au). Employing thick BCP layer (≈15 nm) caused s-shaped JV curve due to charge accumulation at interfaces. The nonlinearity effect was also explored for devices with s-shaped JV and established that device parameters... 

    Synthesis and Characterization of Nanocluster Polyoxometalates as Catalysts in Oxidation and Coupling Reactions

    , Ph.D. Dissertation Sharif University of Technology Hosseini, Hadigheh Sadat (Author) ; Bagherzadeh, Mojtaba (Supervisor)
    In this study, a series of polyoxometalates nanoclusters is synthesized and their catalytic properties have been investigated in oxidation and coupling reactions. In the first and second sections, {Mo36} nanoclusters are primarily prepared. Then, the mesoporous silica, as a solid surface with a regular chanals and cavities through electrostatic interactions between polyoxo anions and amine functional groups with positive charge, is used to stabilize the nanocluster as well as the final structure of SBA-15-NH3 +•{Mo36}- formed. As a green and environmentally friendly substrate, natural zeolite is used to stabilize the nanoclusters and the {Mo36}@zeolite obtained. Both heterogeneous catalysts... 

    Synthesis, Characterization and Application of Inorganic Nanosystems based on Biocompatible and Highly Tunable Materials for Targeted Delivery and Release of Gene and Drug

    , Ph.D. Dissertation Sharif University of Technology Rabiee, Navid (Author) ; Bagherzadeh, Mojtaba (Supervisor)
    In this dissertation, an attempt has been made to prepare a library from most of the inorganic and organic compounds in order to strengthen the use of nanosystems for the purpose of controlled delivery and release of drugs and genetic material. In this regard, a complete set of compounds based on metal nanoparticles, layered double hydroxides, metal-organic frameworks, graphene oxide and carbon nanotubes were designed, synthesized and characterized, and nanocomposites and hybrids of them based on palladium, zinc, copper and nickel were designed as well. The nano-stable system is designed with positive surface potential, very low cytotoxicity, biodegradability and acceptable environment as... 

    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... 

    Reducing ion migration in methylammonium lead tri-bromide single crystal via lead sulfate passivation

    , Article Journal of Applied Physics ; Volume 127, Issue 18 , April , 2020 Mahapatra, A ; Parikh, N ; Kumari, H ; Pandey, M. K ; Kumar, M ; Prochowicz, D ; Kalam, A ; Tavakoli, M. M ; Yadav, P ; Sharif University of Technology
    American Institute of Physics Inc  2020
    Surface passivation of organic-inorganic halide perovskites (OIHPs) is a crucial step to annihilate the surface defects and to control the deteriorated ion migration phenomenon. Here, we study the role of lead sulfate (PbSO4) as an effective passivator in OIHP single crystals (SCs). Using impedance spectroscopy, we evaluate the ion migration and electrical properties of lead sulfate-passivated methylammonium lead tri-bromide (MAPbBr3) SCs. We found that the low-frequency impedance response that is assigned to the ionic motion in the MAPbBr3 SC is strongly affected by the inorganic PbSO4 surface treatment. The activation energy corresponding to the ion migration of MAPbBr3 SC is increased... 

    Effect of bromine doping on the charge transfer, ion migration and stability of the single crystalline MAPb(Br: XI1- x)3photodetector

    , Article Journal of Materials Chemistry C ; Volume 9, Issue 42 , 2021 , Pages 15189-15200 ; 20507534 (ISSN) Mahapatra, A ; Prochowicz, D ; Kruszyńska, J ; Satapathi, S ; Akin, S ; Kumari, H ; Kumar, P ; Fazel, Z ; Tavakoli, M. M ; Yadav, P ; Sharif University of Technology
    Royal Society of Chemistry  2021
    Organic-inorganic halide perovskites (OIHPs) have emerged as a promising semiconductor for the fabrication of efficient optoelectronic devices such as photodetectors (PDs). Among all the perovskite compositions, the mixed-halide MAPb(BrxI1-x)3 formulations have gained more attention for photodetection application thanks to their tunable optoelectronic properties and great stability. However, there is still a lack of sufficient understanding of the effect of Br doping on the stability and physical properties of MAPb(BrxI1-x)3 based PDs. In this work, we prepare a series of MAPb(BrxI1-x)3 (x = 0, 0.04, 0.08, 0.12, and 0.16) single crystals (SCs) and investigate the influence of the Br content... 

    Fabrication and Optimization of Organic Inorganic Perovskite Solar Cells Using Vapor Phase Deposition

    , Ph.D. Dissertation Sharif University of Technology Sedighi, Rahime (Author) ; Taghavinia, Nima (Supervisor) ; Tajabadi, Fariba (Supervisor)
    In this research, we focus on study and fabrication of organic inorganic solar cells. We use and optimize various methods such as one-step spin-coating, two-step sequential deposition and vapor-assisted solution process (VASP), to prepare high quality perovskite films. One-step deposition is simplest method for deposition of perovskite films. Although perovskite deposition by this method is very simple, the control of uniformity and surface film morphology is difficult. Chlorine inclusion, optimization of annealing conditions, and a sequential solution-based deposition method have been demonstrated to increase film coverage and uniformity. Hence, we use sequential deposition method for... 

    Immobilization of dioxomolybdenum(VI) complex bearing salicylidene 2-picoloyl hydrazone on chloropropyl functionalized SBA-15: A highly active, selective and reusable catalyst in olefin epoxidation

    , Article Applied Catalysis A: General ; Vol. 475 , April , 2014 , pp. 55-62 ; ISSN: 0926860X Bagherzadeh, M ; Zare, M ; Salemnoush, T ; Ozkar, S ; Akbayrak, S ; Sharif University of Technology
    A novel organic-inorganic hybrid heterogeneous catalyst system was obtained from the reaction of the molybdenum(VI) complex of salicylidene 2-picoloyl hydrazone with mesoporous silica containing 3-chloropropyl groups prepared by a direct synthetic approach involving hydrolysis and co-condensation of tetraethylorthosilicate (TEOS) and 3-chloropropyltrimethoxysilane in the presence of the triblock copolymer P123 as template under acidic conditions. Characterization of the functionalized materials by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), N2 adsorption/desorption, FT-IR and UV-Vis spectroscopy, and thermogravimetric... 

    A study on utilizing different metals as the back contact of CH3NH3PbI3 perovskite solar cells

    , Article Journal of Materials Chemistry A ; Volume 4, Issue 35 , 2016 , Pages 13488-13498 ; 20507488 (ISSN) Behrouznejad, F ; Shahbazi, S ; Taghavinia, N ; Wu, H. P ; Wei Guang Diau, E ; Sharif University of Technology
    Royal Society of Chemistry  2016
    Organic-inorganic halide perovskite solar cells have attracted considerable interest due to their high efficiency and low fabrication cost. Au and Ag are usually used as the back contact metals but have limitations such as Au is too expensive and Ag is unstable. Here, Pt, Au, Ni, Cu, Cr and Ag were studied as the back contact electrodes for perovskite solar cells. We looked at how the work function of metals can affect their photovoltaic characteristics. The compositional and electrical characterizations were studied using X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). The general trend observed was that the shunt resistance and open-circuit voltage... 

    Understanding the effect of chlorobenzene and isopropanol anti-solvent treatments on the recombination and interfacial charge accumulation in efficient planar perovskite solar cells

    , Article Journal of Materials Chemistry A ; Volume 6, Issue 29 , 2018 , Pages 14307-14314 ; 20507488 (ISSN) Prochowicz, D ; Tavakoli, M. M ; Solanki, A ; Goh, T. W ; Pandey, K ; Sum, T. C ; Saliba, M ; Yadav, P ; Sharif University of Technology
    Organic-inorganic lead halide perovskites have emerged as very promising semiconductors with efficiencies exceeding 22% making them a serious candidate for next generation solar cells. All current high performance perovskite solar cells (PSCs), including the most recent world records, were achieved using the so-called anti-solvent method. Here, an anti-solvent, typically chlorobenzene (CB), is used to induce rapid crystallisation of a liquid perovskite precursor resulting in highly homogenous, pinhole-free planar perovskite films. While this has yielded very impressive high-performance results, few efforts have been dedicated to the fundamental understanding of the anti-solvent method. In... 

    Efficient carrier utilization induced by conductive polypyrrole additives in organic-inorganic halide perovskite solar cells

    , Article Solar Energy ; Volume 207 , 2020 , Pages 1300-1307 Zarenezhad, H ; Balkan, T ; Solati, N ; Halali, M ; Askari, M ; Kaya, S ; Sharif University of Technology
    Elsevier Ltd  2020
    The morphology of the perovskite layer, the effective extraction of the charge carriers, and their transport are the main factors determining the power conversion efficiency (PCE) of the perovskite solar cells (PSCs). In this work, we demonstrated that the geometric and electronic structures of the PSCs could be modified by using a conductive polymer additive in the lead (Pb) halide layer prepared by a two-step deposition method. Polypyrrole (PPy) as a conductive polymer is used in the perovskite layers which could increase the PCE of CH3NH3PbI3-xClx mixed-halide PSCs. By adding an optimized amount of PPy, PCE has been raised from 10.4 to 13.2%. PPy acts as a conductive channel facilitating... 

    Recent progress in inorganic and composite coatings with bactericidal capability for orthopaedic applications

    , Article Nanomedicine: Nanotechnology, Biology, and Medicine ; Volume 7, Issue 1 , Feb , 2011 , Pages 22-39 ; 15499634 (ISSN) Simchi, A ; Tamjid, E ; Pishbin, F ; Boccaccini, A. R ; Sharif University of Technology
    This review covers the most recent developments of inorganic and organic-inorganic composite coatings for orthopedic implants, providing the interface with living tissue and with potential for drug delivery to combat infections. Conventional systemic delivery of drugs is an inefficient procedure that may cause toxicity and may require a patient's hospitalization for monitoring. Local delivery of antibiotics and other bioactive molecules maximizes their effect where they are required, reduces potential systemic toxicity and increases timeliness and cost efficiency. In addition, local delivery has broad applications in combating infection-related diseases. Polymeric coatings may present some...