Application In Photovoltaic Cells Research Articles

Grain Growth Studies of Indium Antimonide Thin Films and Its Application in photovoltaic cell

Compound III-V materials are formed when atoms from group Illb of the periodic table combine with atoms from group Vb. The resulting com pounds are both crystalline and semiconducting and contain an equal proportion of both atom types. The Indium antimonide crystal has been used for infrared applications and for the radiation detector applications. Thin films of InSb with a thickness of about 0.12 micrometer are prepared onto well-cleaned glass substrates by employing an e- beam evaporation process. Indium Antimonide thin films are grown onto well cleaned glass substrates at room temperature on cleaned glass substrate in Hind Hivac- Vacuum Coating unit under a vacuum better than 10<sup>−5</sup> Torr. X-ray diffraction studies confirm the polycrystalline of the films and the films show preferential orientation along the (111) plane. The particle size found to about 1100 micrometer of thin film. In this paper we present some of our results concerning the synthesis and crystal growth of indium antimonide compounds . To carry out the synthesis of InSb a suitable mixing furnace was designed and fabricated.

ChemInform Abstract: Our Expedition in Linear Neutral Platinum‐Acetylide Complexes: The Preparation of Micro/Nanostructure Materials, Complicated Topologies, and Dye‐Sensitized Solar Cells

AbstractReview: [53 refs.

Broadening of absorption band by coupled gap plasmon resonances in a near-infrared metamaterial absorber

We propose a strategy to broaden the absorption band of the conventional metamaterial absorber by incorporating alternating metal/dielectric films. Up to 7-fold increase in bandwidth and ∼95% average absorption are achieved arising from the coupling of induced multiple gap plasmon resonances. The resonance coupling is analytically demonstrated using the coupled oscillator model, which reveals that both the optimal coupling strength and the resonance wavelength matching are required for the enhancement of absorption bandwidth. The presented multilayer design is easily fabricated and readily implanted to other absorber configurations, offering a practical avenue for applications in photovoltaic cells and thermal emitters.

“Click” polymerization: A convenient strategy to prepare designer fullerene materials

“Click” polymeric assemblies of fullerenes, thiophenes and aryl compounds were prepared for the first time to study their spectroscopic/chemical/electronic characteristics and possible applications in photovoltaic cells. The GPC and NMR spectroscopic data confirmed a moderate to high degree of polymerization while microscopic pictures showed well-defined arrangements of fullerenes. The FTIR studies indicated that the product is free from starting azide materials, whereas thermogravimetric analysis data suggested a good stability. Band gap of the material was determined using UV–Vis spectroscopy, cyclic voltammetric techniques and compared with computational investigation. The fullerene copolymer was fabricated as acceptor material in a bulk heterojunction photovoltaic cell.

Photovoltaic properties of a new quinoxaline-based copolymer with Thieno[3,2-b]thiophene side chain for organic photovoltaic cell applications

A new quinoxaline-based electron-accepting building block with thieno[3,2-b]thiophene side chains was synthesized and copolymerized with the alkoxy-substituted benzodithiophene (BDT) donor building block to obtain poly[(4,8-bis[(2-butyloctyl)oxy]-benzo[1,2-b:4,5-b′]dithiophene)-alt-(2,3-bis(5-octylthieno[3,2-b]thiophene-2-yl)-5,8-di(thiophen-2-yl)quinoxaline)] (PBDT- TTDTQx) copolymer. To compare the effect of the addition of the thieno[3,2-b]thiophene side chain in the quinoxaline moiety, an analogous copolymer with a thienyl side chain in the quinoxaline unit was also synthesized to yield the poly[(4,8-bis[(2-butyloctyl)oxy]-benzo[1,2-b:4,5-b′]dithiophene)-alt-(2,3-bis(5-octylthiophene-2-yl)-5,8-di(thiophen-2-yl)quinoxaline)] (PBDT-TDTQx) copolymer. The optical, electrochemical, morphological, and photovoltaic properties of the two polymers were investigated. Bulk heterojunction photovoltaic devices were fabricated using the polymers as a p-type donor and [6,6]-phenyl C71-butyric acid methyl ester (PC71BM) as the n-type acceptor. The power conversion efficiencies of the devices fabricated using PBDT-TTDTQx and PBDT-TDTQx are 3.42 and 2.26%, respectively. The replacement of the alkylthienyl moiety with thieno[3,2-b]thiophene on quinoxaline could expand the UV–visible absorption range due to extended π-conjugation and also enhance the crystallinity of the polymer.

The ferroelectric photovoltaic effect of BiCrO3/BiFeO3 bilayer composite films

This work involves an investigation of the structure, ferroelectricity, optical band-gap, photovoltaic spectral response and J-V performance of BiCrO3/BiFeO3 bilayer composite films prepared via the solution-gelation technique. It is shown that the enhanced ferroelectric properties are observed for BiCrO3/BiFeO3 bilayer composite films by interaction resulting from the coupling between BiFeO3 and BiCrO3 layers. The photovoltaic spectral responses of the normalized current for BiCrO3/BiFeO3 bilayer composite films presents a noteworthy red-shift towards visible region compared with the pure BiFeO3 films and the pure BiCrO3 films. Thus photovoltaic response is attributed to the narrow band-gap of BiCrO3/BiFeO3 bilayer composite films. The short circuit current density and open circuit voltage of the BiCrO3/BiFeO3 bilayer composite films under white-light illumination are much higher than the values of BiFeO3 and BiCrO3 films. The present work provides an available way of controlling photovoltaic response of ferroelectric films and accelerating its application in light sensors, light drivers and ferroelectric photovoltaic cells.

Non-injection gram-scale synthesis of cesium lead halide perovskite quantum dots with controllable size and composition

Metal-halide perovskites are novel optoelectronic materials that are considered good candidates for solar harvesting and light emitting applications. In this study, we develop a reproducible and low-cost approach for synthesizing highquality cesium lead halide perovskite (CsPbX3, X = Cl, Br, and I or Cl/Br and I/Br) nanocrystals (NCs) by direct heating of precursors in octadecene in air. Experimental results show that the particle size and composition of as-prepared CsPbX3 nanocrystals can be successfully tuned by a simple variation of reaction temperature. The emission peak positions of the as-prepared nanocrystals can be conveniently tuned from the UV to the NIR (360–700 nm) region, and the quantum yield of the as-obtained samples (green and red emissions) can reach up to 87%. The structures and chemical compositions of the as-obtained NCs were characterized by transmission electron microscopy, X-ray diffraction, and elemental analysis. This proposed synthetic route can yield large amounts of high-quality NCs with a one-batch reaction, usually on the gram scale, and could pave the way for further applications of perovskite-based light-emitting and photovoltaic solar cells.

Our Expedition in Linear Neutral Platinum-Acetylide Complexes: The Preparation of Micro/nanostructure Materials, Complicated Topologies, and Dye-Sensitized Solar Cells.

During the past few decades, the construction of various kinds of platinum-acetylide complexes has attracted considerable attention, because of their wide applications in photovoltaic cells, non-linear optics, and bio-imaging materials. Among these platinum-acetylide complexes, the linear neutral platinum-acetylide complexes, due to their attractive properties, such as well-defined linear geometry, synthetic accessibility, and intriguing photoproperties, have emerged as a rising star in this field. In this personal account, we will discuss how we entered the field of linear neutral platinum-acetylide chemistry and what we found in this field. The preparation of various types of linear neutral platinum-acetylide complexes and their applications in the areas of micro/nanostructure materials, complicated topologies, and dye-sensitized solar cells will be summarized in this account.

The ferroelectric photovoltaic spectral response regulated by band-gap in BiFe0.9Cr0.1O3 films

BiFe0.9Cr0.1O3 solid solution films have been prepared via the solution-gelation technique. The structure, ferroelectricity, optical band-gap, and photovoltaic spectral response were investigated. It shows that the photovoltaic spectral responses for BiFe0.9Cr0.1O3 films shift towards visible region compared with the pure BiFeO3 films. The halfway points of the full width at half-maximum are detected at 378nm and 420nm, closely corresponding to the measured band-gap of BiFeO3 and BiFe0.9Cr0.1O3 films. Thus photovoltaic behaviors are attributed to the narrower band-gap derived from the rearrangement of molecular orbital and rhombohedral distortion. The present work provides an available way of controlling photovoltaic response of ferroelectric films and accelerating its application in light sensors, light drivers and ferroelectric photovoltaic cells.

(Invited) Boron Subphthalocyanines, Boron Subnaphthalocyanines and Silicon Phthalocyanines - All Very Versatile Materials for Organic Photovoltaics

For some time, our group has been focused on the design and synthesis of derivatives of boron subphthalocyanine (BsubPc) for application in organic electronics with a specific focus on organic photovoltaics and light emitting diodes; during this presentation however I will focus specifically on their application in organic photovoltaics. I will begin by focusing on our efforts with regards to synthetic variants of BsubPcs and their application in planar heterojunction organic photovoltaic cells (OPVs, organic solar cells, OSCs). After summarizing this work, I will then outline our very recent results where we took BsubPc based planar heterojunction organic photovoltaic cells and put them in the ambient environment on the roof of our building in downtown Toronto during the summer of 2015. What we found was that during that time, the BsubPc based cells were remarkably stable. We were able to form a structure property relationship to their stability in the ambient environment. Recently, we have also shown that BsubPcs are deficient triplet harvesters from pentacene. They are amongst only a few materials known to facilitate this process.In parallel we have also been exploring the concept of complementary absorption engineering by either the chemical modification of BsubPcs or by pairing BsubPcs with alternative materials having complementary absorption profiles. For example, we have shown that a highly substituted BsubPc can yield a red shifted absorption profile of approximately 100 nm. This shift is equivalent to that of boron subnaphthalocyanines (BsubNcs). We have also recently been exploring the chemistry of BsubNcs. I will outline our results and the application of our BsubNcs in OPVs.[1] Time permitting, I will also outline the pairing of a BsubPc with phosphorus tetrabenzotriazacorrole [a phthalocyanine analogue] which yielded a unique gray organic photovoltaic cell and our group’s recent exploration of the bulk-heterojunction OPV space whereby BsubPcs are fullerene alternatives, although we are not the first to do so.[2]Finally, during last year’s meeting, I outlined how our group’s recent exploration of other p-block metal phthalocyanines (Pcs) including Pcs of aluminum, silicon, germanium and phosphorous yielded the conclusion that silicon phthalocyanines (SiPcs) can also be applied as fullerene alternatives/acceptors in organic photovoltaic cells. Our conclusion at the time was that phenoxylation enhances the performance of SiPcs as an electron transporting/accepting materials. Over the past year we have enhanced this conclusion and formed an initial structure property relationship that gives a road map to synthetic alternatives of SiPcs that may ultimately yield higher performing OPVs. I will outline this structure property relationship and our future work in this area.Coauthors will be cited as appropriate throughout the presentation.

Synthesis and Characterization of Conducting Copolymers PANi‐PTh for Photovoltaic Cell Applications

SummaryDuring the last decade the field of polymer photovoltaic has seen a tremendous improvement in both device efficiency and understanding of the underlying optical properties. A class of new conjugated copolymers containing a donor polythiophene (PTh) and polyaniline (PANi) was synthesized via Chemical polymerization by using TiCl4 as a oxidizing agent. The resulting copolymer was characterized by FTIR, XRD, FE‐SEM analysis. We fabricated organic photovoltaic cell device by using as‐prepared composite. Copolymer photovoltaic cell of a bulk heterojunction was fabricated on ITO glass plates with the structure of ITO/copolymer/ITO. The photovoltaic parameter such as open‐circuit voltage (Voc), fill factor (FF), short‐circuit current (Isc), were measured. The conversion efficiency for as fabricated photovoltaic cell was found to be 0.23%.

Controlled donor-accepter ratio for application of organic photovoltaic cells by alternative intermittent electrospray co-deposition

Because co-deposition method has been utilized in a conventional thermal evaporation process to realize graded donor-acceptor architectures, we investigated an alternative intermittent electrospray co-deposition method for solution-processed organic photovoltaic cells. In this method, two solutions of poly(3-hexylthiophene-2,5-diyl) (P3HT) and phenyl-C61 butyric acid methyl ester (PCBM) were alternatively deposited using high-voltage pulse. Thus, the P3HT:PCBM blend thin film could be deposited even in a vacuum-free experimental setup. The optimum pulse width was found to be greater than 6 s to avoid an unexpected charge to the adjacent glass capillary, which causes the instable electrospray. The P3HT molecular ordering estimated from Raman spectroscopy and grazing incidence X-ray diffraction patterns was comparable to that estimated from the spin-coated device. In addition, the P3HT:PCBM ratio of the deposited thin film could be controlled by changing the ratio of the pulse width for the P3HT and PCBM solutions and was evaluated from the ultraviolet–visible absorption spectrum. Finally, a two layered bulk heterojunction structure with P3HT:PCBM was successfully demonstrated, leading to a maximum photoconversion efficiency of 3.1%. This value was 1.4-fold higher than that of the uniformly mixed bulk heterojunction device because of the high carrier-collection efficiency.

Surface Modification by UV-Irradiation for Organic Photovoltaic Solar Cells Application

Surface Modification by UV-Irradiation for Organic Photovoltaic Solar Cells Application

Electronic quality improvement of crystalline silicon by stain etching-based PS nanostructures for solar cells application

In the present work, the impact of stain etching-based Porous Silicon (PS) nanostructures on both the effective lifetime and photoluminescence were examined. Results showed that stain etching-based PS nanostructures increase the effective lifetime from 3μs (un-etched samples) to 48μs (following 8min etching time) at a minority carrier density (Δn) of 1015cm−3 and drastically decrease the silicon surface reflectivity from about 28% to approximately 7%. These results allowed to correlate between the rise of the effective lifetime values and the photoluminescence intensity; which in turn depends on the effects of hydrogen and oxygen passivation. Consequently, the electronic quality of the multi-crystalline silicon improved significantly leading to high photovoltaic quantum efficiency response. This low-cost stain etching-based PS nanostructures process could potentially be applied in the photovoltaic cell technology and applications.

Tuning of Light Trapping and Surface Plasmon Resonance in Silver Nanoparticles/c-Si Structures for Solar Cells

In this work, we investigate silver (Ag) nanoparticle-related plasmonic effect on light absorption in Si substrate. Ag nanoparticles (Ag-NPs) deposited on top of Si were used to capture and couple incident light into these structures by forward scattering. We demonstrate that we can control nanoparticle size and shape while varying deposition time and annealing parameters. By the increase of the total time of the reaction process, morphology of Ag-NPs evolutes affecting the number and the width of surface plasmon resonance peaks, whereas for changed annealing parameters (temperature and time), the effect is more pronounced on the broadening and the position of peaks. Specific morphology of Ag-NPs can exhibit an interesting enhancement of optical properties which enables plasmon-related application in photovoltaic solar cells.

Synthesis of new dithieno[3,2-b:2′,3′-d]pyrrole (DTP) units for photovoltaic cells

Three new dithieno[3,2-b:2′,3′-d]pyrrole units (DTPA1–3) based on the truxene core have been designed and synthesized for a potential application in photovoltaic cells. One of these units (DTPA1) has been employed to construct a new organic dye (M47), exhibiting a higher solar-to-electrical energy conversion efficiency when compared to reference dyes (M48 and M49) under the same conditions. Absorption spectra, electrochemical cyclic voltammetry, theoretical calculations, current voltage curves and controlled intensity modulated photovoltage spectroscopy have been investigated. M47 sensitized solar cells employing a cobalt electrolyte afford a short circuit photocurrent of 12.1 mA cm−2, an open circuit voltage of 758 mV, and a fill factor of 0.56, corresponding to an overall power conversion efficiency of 5.1% under standard AM 1.5 sunlight. These results suggest that the truxene-substituted dithieno[3,2-b:2′,3′-d]pyrrole derivatives are promising candidates for photovoltaic cells.

Main-chain polyoxometalate-containing donor–acceptor conjugated copolymers: synthesis, characterization, morphological studies and applications in single-component photovoltaic cells

Single-component solar cells of main-chain polyoxometalate-containing donor–acceptor conjugated copolymers show efficiencies comparable to those conjugated polymers with covalently bonded fullerenes.

Evaluation of the electronic properties of perfluorophenyl functionalized quinolines and their hybrids with carbon nanostructures.

Hybrid materials based on perfluorophenyl functionalized quinolines directly attached onto the sp(2) hybridized surface of carbon nanostructures have been prepared and studied herein along with their precursor semiconducting small molecules. Tails of different polarities have been used so that the molecules would present improved solubility and controllable affinity for the selected substrates. These materials were evaluated for their electronic and electrochemical properties for potential application in organic photovoltaic solar cells (OPVs), using UPS, XPS and CV measurements after deposition onto oxygen plasma cleaned Si wafers or solvent treated ITO coated glass. A weak interaction between the fluorine atoms and both the Si and the ITO substrates was observed by XPS. The extent of this interfacial interaction was found to be related to the orientation of the quinoline moieties on the organic layer. Moreover, the combination of XPS and UPS analyses showed that the absolute energy value of the HOMO level increased as the amount of surface fluorine atoms increased. CV measurements revealed that hybridisation of the small molecules with carbon nanostructures decreases the materials' energy gap and increases the absolute energy value of the LUMO level. These features prove the efficiency of the proposed method to produce materials with controlled energy levels for solar cell devices.

Carbohydrate-based block copolymer self-assemblies: Sub_10nm highly nanostructured thin films

Event Abstract Back to Event Carbohydrate-based block copolymer self-assemblies: Sub_10nm highly nanostructured thin films Tiffany Gomez1*, Issei Otsuka1, Cécile Bouilhac2*, Eric Reynaud1*, Sami Halila1* and Redouane Borsali1* 1 CERMAV-CNRS, Grenoble Alpes University, Physico-chemistry and self-assembly of glycopolymers, France 2 Université de Montpellier, Equipe Ingénierie et Architectures Macromoléculaires, France Introduction: The design of smaller, faster, more efficient devices is a major scientific and technological challenge, driven in part by a constant need for smaller features and higher resolution patterns. To this end, self-assembling soft materials[1],[2] continue to play an important role in societal and economical goals for smaller and hierarchically nanostructured devices. Block copolymer thin films belong to this class of materials where self-assembly takes place on nanometer length scales. This makes them ideal for emerging nanotechnologies, including applications, for instance, in nano-templating, nano-porous membranes, organic optoelectronics and anti-reflection coatings. Nano-organized thin films are made today from synthetic di-block copolymers (petroleum) and their self-assembly is constrained to 20 nm resolution (domain and size spacing). This is a consequence of the small incompatibility between both blocks (typical model system: PS-PMMA)[3]. To make those systems more attractive for bit-patterned media applications, attempts were made to achieve smaller domains and sizes. These attempts have, however, had only limited success. Materials and Methods: Indeed, to date, numerous studies have been focused on the self-assembly of petroleum-based BCPs for potential applications in multidisciplinary fields, such as nanoparticles for drug delivery, or nano-organized films for biosensors, or nanolithography, etc. Such materials are derived from fossil resources that are being rapidly depleted and have negative environmental impacts. In contrast, carbohydrates are abundant, renewable and constitute a sustainable source of materials. Such materials (bio-sourced block copolymer systems) have been obtained using "click" chemistry consisting of linking oligo/polysaccharide to another block (synthetic or natural). Those bio-based systems are currently attracting much interest in various sectors and their industrial applications at the nanoscale level will have to expand quickly in response to the transition to a bio-based economy. Results and Discussion: To overcome these two bottlenecks -substitution of petroleum molecules and resolution limit - R. Borsali et al[3]-[6] have recently made an important breakthrough by using carbohydrate-based block copolymer and have achieved the highest resolution ever reached to date (5 nm features)-(see illustrations on Figures 1 and 2). We will in this paper present new and recent results on the self-assemblies of oligosaccharide-based block copolymer (synthetic block-Maltoheptaose, where synthetic block stands for Polystyrene or Polyisoprene) leading to highly nanostructured thin films (sub-10nm resolution). Conclusion: This new class of carbohydrate based-block copolymer systems lead to nano-organized thin films (resolution sub_10nm) that could open the horizon to numerous applications in flexible opto-electronics, biosensors, photovoltaic cells and new generation of nanolithography. The authors acknowledge the CNRS, Greenanofilms project (Seventh Framework Program under grant agreement n° 603519), Institut Carnot Polynat and Labex ARCANE for financial supports.

Polymer substrates for flexible photovoltaic cells application in personal electronic system

The article presents an overview of polymeric materials for flexible substrates in photovoltaic (PV) structures that could be used as power supply in the personal electronic systems. Four types of polymers have been elected for testing. The first two are the most specialized and heat resistant polyimide films. The third material is transparent polyethylene terephthalate film from the group of polyesters which was proposed as a cheap and commercially available substrate for the technology of photovoltaic cells in a superstrate configuration. The last selected polymeric material is a polysiloxane, which meets the criteria of high elasticity, is temperature resistant and it is also characterized by relatively high transparency in the visible light range. For the most promising of these materials additional studies were performed in order to select those of them which represent the best optical, mechanical and temperature parameters according to their usage for flexible substrates in solar cells.