Application In Photovoltaic Cells Research Articles

Synthesis and characterization of novel conjugated copolymers for application in third generation photovoltaic solar cells

An organic photovoltaic cell (OPV) is a subcategory of the third generation of photovoltaic cells. Advantages of OPV include lightness and ease of production in industrial scale. This work proposes the synthesis and characterization of two novel random and block copolymers for OPV containing fluorene (F), thiophene (T) and benzothidiazole (B) as structural units. Polymerizations were performed via the Suzuki-Miyaura mechanism. The yields obtained for both copolymers were around 65% with corresponding molar masses measured by GPC of 3394 and 4598 g/mol. From TGA, the onset degradation temperature was approximately 415 °C, while the maximum degradation temperature was around 440 °C, for both copolymers. FTIR and NMR analyses confirmed the ratio of aliphatic and aromatic carbons in the structure of both copolymers. Difference of chaining between both copolymers was verified by 13CNMR and XRD. The energy values of HOMO were -5.76 eV for random and -5.74 eV for block copolymer. Through UV-Vis spectroscopy, optical bandgaps of 2.39 and 2.34 eV were obtained for random and block polymers, respectively. Finally, LUMO energy levels of -3.37 eV (random) and -3.40 eV (block) were calculated by subtracting the optical band gap from the HOMO energy. Mobility measurements by JV method were performed in pure polymer films, rendering 1.91 × 10−6 and 1.35 × 10-8 cm2 /V.s for random and block copolymers, respectively. Copolymers were applied in conventional and inverted devices, presenting diode behavior. Energy efficiency obtained was higher for the block copolymer, which was consistent with the obtained interplanar distances estimated by XRD.

Visible-Light Photocurrent in Nanostructured High-Pressure TiO2-II (Columbite) Phase

Titanium oxide (TiO2), with the anatase and rutile structures, has been widely studied for photovoltaic and solar cell applications, but its main drawback is large bandgap, which limits its activit...

Economical, Green Synthesis of Fluorescent Carbon Quantum Dots from Lac Extract

Fluorescent carbon quantum dots (FCDs) have attracted tremendous interest because of their advantageous characteristics of cost effectiveness and fluorescent nature. In this study, we developed a simple, economical and effective method for the green synthesis of fluorescent carbon quantum dots (FCDs) from Lac of Butea monosperma host tree, a renewable and sustainable resource. The synthesis method involves the low cost hydrothermal process using the Lac extract as a carbon source. The as-synthesized FCDs were characterized by Xray diffraction (XRD), Transmission electron microscopy (TEM) and Spectrofluorophotometer. The synthesized FCDs possess stable good water solubility as well as high quantum yield. The results suggest that the proposed FCDs could be utilized for photovoltaic cell, bio imaging, drug delivery and bio-sensor applications.

Photogenerated-Carrier Separation and Transfer in Two-Dimensional Janus Transition Metal Dichalcogenides and Graphene van der Waals Sandwich Heterojunction Photovoltaic Cells

Two-dimensional (2D) Janus transition metal dichalcogenides (JTMDs) show direct band gaps and strong visible light absorption with promising applications in photovoltaic cells. Here, we investigate the electronic structures and dynamics of photogenerated carriers in 2D JTMDs and graphene van der Waals sandwich heterojunction (G/JTMDs/G) photovoltaic cells by using first-principles calculations. We find that the intrinsic built-in electric field in JTMDs results in an asymmetry potential, which can be used to effectively enhance the separation and transfer of photogenerated carriers from JTMDs to different graphene layers with a preferred direction within hundreds of femtoseconds in the G/JTMDs/G heterostructures. Furthermore, the photogenerated electrons (holes) can be transferred from monolayer MoSSe (MoSeTe) to the graphene sheets by the Se side with a lower (higher) potential, while the transfer of the photogenerated holes (electrons) is prohibited due to the large separation between the donor and acceptor states.

Cd(Zn, S)Se quaternary thin films for electrochemical photovoltaic cell application

In this study, Cd1−xZnxSySe1−y (0 ≤ x = y ≤ 0.35) photoelectrodes are deposited via inexpensive facile chemical bath deposition. The effects of Zn and S doping on the compositional, microstructural, electrical, and optical properties of thin films were analysed. The electrochemical photovoltaic (EPV) cell of configuration Cd1−xZnxSySe1−y/0.25M sulfide/polysulfide/C was assembled to examine the different performance parameters in light and in dark conditions. An EPV cell fabricated with the Cd1−xZnxSySe1−y (0 ≤ x = y ≤ 0.075) photoelectrode exhibited a maximum photoconversion efficiency of 3.18%. This performance can be attributed primarily to the enhanced light-absorption ability of the material because of the enhanced rough microstructure and low recombination of photo-injected electrons with the electrolyte. The photovoltaic (PV) performance is significantly enhanced after doping CdSe with Zn and S.

Simulation and experimental validation of solar radiation distribution on the absorber of a line-axis asymmetric compound parabolic concentrator

This paper reports the development and application of a new practical photovoltaic (PV) cells based device to measure the solar radiation flux produced by non-imaging Compound Parabolic Concentrators (CPCs) on cylindrical absorbers. The flexible experimental device comprises 12 discrete miniature PV panels that measure solar radiation on the surface of a cylindrical absorber. The device has been used to evaluate the performance of an asymmetric CPC system and results validated with a computer-based Ray Tracing Model. The study attained significant agreement between outdoor results of the experimental device and results of the ray tracing simulation with a difference of <9% in optical efficiencies. The non-imaging reflector illuminates a targeted section of the absorber of a horizontal east-west thermal diode Integrated Collector Storage Solar Water Heater. During outdoor testing, the experiments indicated a local concentration ratio reaching 1.4 suns on the targeted section of the absorber vessel surface for incidence angles -30°≤θi≤30°, confirming technical suitability of the asymmetric CPC for deployment in locations at equatorial latitudes.

Fabrication and Characterization of Graphene Incorporated Cu Based Perovskite in Application of Perovskite Solar Cell under Ambient Condition

In this work, we demonstrate the synthesis and characterization of Cu-based thin film perovskites and their prospective application in photovoltaic cells and light-harvesting devices, which is lead(Pb) free and environmental friendly. We studied valuable part of graphene for stability issue in CH3NH3CuCl3(MACuCl3) Perovskites solar cell and improved band gap 2.61 eV to 2.56 eV as well. Copper ions represented responsible of this materials for the bright green photoluminescence. For assimilating MACuCl3 and G-MACuCl3 based Perovskites, solar cells architectures and photovoltaic performance are argued among them. The main limitations for the solar cell efficiency were found the arrangement of insubstantial mass and high absorption coefficient of the electrons as well. As per as our knowledge, this work is demonstrated of the prospective of thin film MACuCl3 and G-MACuCl3 perovskite as light absorber and puts down the establishment for additional development of perovskite solar cell as alternative of lead-free materials.

Application of photovoltaic cells as a source of energy in unmanned aerial vehicle (UAV) – case study

During last years, renewable energy sources (RES) find their way into the transportation industry. Among the units which may be powered directly with renewable energy, the UAVs (unmanned aerial vehicles) market is undergoing a rapid development. In this case mainly the solar energy is used. Photovoltaic modules are mainly located on the wings, so it is often necessary to use flexible PV cells which have lower efficiency than the flat ones. This study proves that airfoil geometry modifications by partial flattening are not beneficial from the aerodynamic point of view. The lower energy conversion on photovoltaic panels must be balanced by energy storage and energy management systems. The performance of exemplary installation mounted on AGH Solar Plane has been modelled with TRNSYS software. Obtained results allowed to establish the amount of produced, stored and used energy in six different months.

Rational design of a main chain conjugated copolymer having donor–acceptor heterojunctions and its application in indoor photovoltaic cells

P(BDBT-co-NDI2T) exhibited a strong absorption band, which overlapped with the emission spectrum of an LED lamp and it exhibited a high power conversion efficiency of 12.70% under the LED lamp (@500 lux).

On the effect of pattern substitution and oligo(ethylene oxide) side-chain modification on thiophene-quinoxaline copolymers and their applications in photovoltaic cells

Abstract The molecular design of conjugated polymers for efficient organic photovoltaic devices (OPVs) providing advantageous processing properties, namely solubility in low toxic solvents as ethanol, is an important issue for the progress of OPV technology. In this work, the pattern substitution and chemical nature of the side chain, either n-alkoxy or oligo(ethylene oxide) groups, in alternating thiophene-quinoxaline copolymers is varied and their effect in polymer chain grow, solubility and optical spectra is thoroughly analyzed in light of quantum mechanical calculations. Although the polymer with oligo(ethylene oxide) groups exhibited good solubility in ethanol, it was found that substituting in both meta- and para-positions of the peripheral phenyl rings attached to the quinoxaline groups causes smaller molecular weight, lower solubility in chlorinated solvents and poorer performance in photovoltaic devices. The theoretical studies revealed differences in the most energetically favored conformers for each case of the polymers'substitution pattern that can justify the observed results.

Interfacial Engineering through Chloride-Functionalized Self-Assembled Monolayers for High-Performance Perovskite Solar Cells.

The family of organic-inorganic hybrid perovskite (OIHPs) materials is one of the most promising for very high-efficiency photovoltaic solar cell application. In the present work, the effect of a series of self-assembled monolayers placed at the TiO2-perovskite junction, on the functioning of triple cation perovskite solar cells has been investigated. We show that employing 4-chlorobenzoic acid leads to the marked boosting of the solar cell performances. The starting pristine cell had a power conversion efficiency (PCE) of 20.3% and the chemical engineering permitted to reach a PCE up to 21.35%. Our experimental study completed by density functional theory calculations and modeling show that this progress is due to the reduction of interfacial states, to the improvement of the quality of the OIHP material and to the structural continuity between TiO2 and the OIHP. Especially, we demonstrate that the interfacial chemical interactions are important to consider in the design of highly efficient devices.

Performance of A Standalone Solar Photovoltaic System

This paper presents a performance study on a standalone solar photovoltaic system. The application of photovoltaic solar cells is increasingly prevalent in Indonesia. Indonesia is a tropical country, where throughout the year, get sun exposure. This condition strongly supports the use of photovoltaic solar cells as a source of electrical energy. Many small to large-scale solar power generation systems have been built in Indonesia. On a small scale in the form of a standalone system, solar power plants are usually used as secondary power plants, where primary power plants still come from state electricity companies. In this research, the analysis of the performance of solar power plants for standalone systems with a capacity of 400 Wp. Efforts to improve the performance of solar cells are made by using a mirror reflector. The results showed that the mirror reflector could increase the output power of photovoltaic solar cells.

TiO2/Cu2O heterojunctions for photovoltaic cells application produced by reactive magnetron sputtering

In this work, TiO2/Cu2O heterostructures were obtained in a two-step process with a direct current magnetron sputtering method. We studied the morphological properties and composition of the thin films by scanning electron microscopy. Optical properties and energy bands at the heterojunction were recorded using a spectrophotometer. Additionally, the current–voltage characteristics examined in both total darkness and with illumination were estimated to have an irradiation (radiation flux divided by area) of 1000 W/m2.

Direct (hetero)arylation polymerization for the synthesis of donor–acceptor conjugated polymers based on N‐benzoyldithieno [3,2‐b:2′,3′‐d]pyrrole and diketopyrrolopyrrole toward organic photovoltaic cell application

AbstractIn this research, new donor–acceptor (D‐A) photovoltaic polymers were synthesized from dithieno[3,2‐b:2′,3′‐d]pyrrole electron donor derivatives, including N‐benzoyldithieno[3,2‐b:2′,3′‐d]pyrrole and N‐(4‐hexylbenzoyl)dithieno[3,2‐b:2′,3′‐d]pyrrole, in combination with the electron deficient unit 2,5‐bis(2‐ethylhexyl)‐3,6‐di(thiophen‐2‐yl)‐2,5‐dihydropyrrolo[3,4‐c]pyrrole‐1,4‐dione via direct (hetero)arylation polymerization. The D‐A conjugated polymers obtained were characterized via 1H NMR, gel permeation chromatography, Fourier transform infrared spectroscopy, DSC, XRD, photoluminescence and UV–visible methods. In addition, these D‐A polymers were used as activated layers in bilayer and bulk heterojunction structures for the fabrication of organic photovoltaic cells. © 2019 Society of Chemical Industry

Material removal and surface generation mechanisms in diamond wire sawing of silicon crystal

Silicon crystal is usually first cut into wafers in the applications of electronic devices and photovoltaic solar cells. At present, fixed abrasive wire sawing technology has been widely used in slicing. The mechanism of material removal and surface generation during wire sawing is the key basic problem to study the surface quality of sliced wafers, which is important to realize high-precision slicing. This paper presents theoretical analysis on the relationship between the average cutting depth of abrasives distributing in different positions along the wire circumferential surface and the process parameters. The wire sawing experiments of single crystal silicon were carried out, then the morphologies of sawn surface and swarf were observed, the surface roughness was measured and analyzed, the material removal and surface generation mechanism of single crystal silicon cut by electroplated diamond sawing wire were addressed. Research results show that there is an approximate non-linear increasing relationship between the average cutting depth of the abrasives and the ratio of the workpiece feed speed to the wire speed, and the abrasives cutting depth and surface roughness of sliced wafers increases with the increasing of ratio value. It is difficult to obtain the sliced surface in a fully ductile mode of material removal in the actual wire sawing process because there are always a small amount of abrasives with high protrusion on the wire surface whose cutting depths are greater than the critical ductile regime cutting depth, but adopting a low ratio can make the generation of the sliced wafer surface in near-ductile or local-ductile material removal mode which can produce high quality wafer surface. This research is expected to be useful in optimizing the combination of process parameters in fixed abrasive diamond wire saw precision slicing of silicon wafers.

Surface passivated aqueous mediated synthesis of CdTe QDs: potential nano thin films

Cadmium Telluride (CdTe) semiconductor quantum dots (QDs) have potential applications in optoelectronics, biomedical and photovoltaic solar cells. In spite of having tremendous potentiality in the applied fields, the literature reveals scanty reports about the low cost, environmentally sustainable and ambient temperature methodology for the synthesis of CdTe QDs. Currently, the aqueous synthesis route is more promising due to its more reproducibility, less toxicity and biocompatibility. However, the reported aqueous methods also find defect associated photoluminescence due to the presence of surface trap states, which diminish luminescence property drastically with red-shift emission. The present work reportssynthesis of surface passivated FCC cubic crystalline CdTe QDs (size ∼4–7 nm from x-ray diffraction and transmission electron microscopic techniques) in an atom economic greener way, where Polyvinylpyrollidone is acting as capping agent. Polyvinylpyrollidone effectively passivates the surface of QDs by quenching surface dangling bonds, which is proved by photoluminescence investigation with quality single band edge emission at 500 nm (λex = 335 nm, Eg = 2.48 eV). The characterized CdTe nanomaterials were subjected to the fabrication of thin films by simple and cost-effective spin coating method.

Polyaniline–graphene quantum dots (PANI–GQDs) hybrid for plastic solar cell

Polyaniline–graphene quantum dots (PANI–GQDs) are considered as an important candidate for applications in photovoltaic cells. In this work, GQDs were prepared using sono-Fenton reagent from reduced graphene oxide (rGO). PANI–GQD hybrid was also synthesized using the chemical in situ polymerization method. The synthesized materials were characterized using UV–visible (UV–Vis) spectroscopy, photoluminescence (PL) spectroscopy, current–voltage (I–V) characteristic, thermal gravimetric analysis (TGA), Raman spectroscopy, and X-ray diffraction (XRD). Dynamic light scattering was also used to estimate the lateral size of GQDs. The enhanced visible-light absorbance in the hybrid was confirmed by UV–Vis analysis and the decrease in intensity around 3461 cm−1 in FT-IR spectra was due to the interaction between functional groups of PANI with GQDs. This led to improved thermal stability and conductivity as observed from TGA and I–V analysis, respectively. Moreover, the Raman spectrum for PANI–GQDs showed a decrease in the peak at ~ 1348 and ~ 1572 cm−1 as compared to PANI and GQDs. Similarly, from the XRD profile of PANI–GQDs, a shift in peak was observed due to an alteration in the microstructure. A sandwich device with cell structure glass/ITO/PANI–GQDs/Al was fabricated and its application was tested. Current density–voltage (J–V) curve of the device was measured with a Keithley SMU 2400 unit under an illumination intensity of 100 Wm−2 simulating the AM 1.5 solar spectrum. The hybrid exhibited photovoltaic properties, and 0.857% efficiency was observed in response to the applied voltage. This work suggests that PANI can be used as an alternative material for photovoltaic cells.

Electronic Structures and Magnetic Properties of Transition Metal Doped CsPbI3 Perovskite Compounds by First-Principles Calculation

Transition metal doped cesium lead halide (CsPbI3) perovskite compounds were studied for application in photovoltaic solar cells. Electronic structures, chemical shifts of 207Pb and 127I-NMR, vibration modes in infrared and Raman spectra of transition metals (Mn2+, Fe2+ or Cu2+)-doped CsPbI3 perovskite compounds were studied by the first-principles calculation using density functional theory. The CsPb(Fe)I3 perovskite crystals had a slight perturbation of crystal field in the coordination structure. The electron density distribution was delocalized on the 5p orbital of I atom, the 3d orbital of Fe atom and the 6p orbital of Pb atom. The first excited process was based on ligand metal charge transfer from the 5p orbital on I atom to the 3d orbital of Fe atom. The chemical shifts of 127I-NMR were associated with the electron correlation of electron-nuclear spin interaction and nuclear quadrupole interactions based on electron field graduate. The asymmetric vibrations of Pb–I bonds stretching mode related to electron conductivity with scattering of the carrier diffusion as phonon effectiveness. The slight perturbation of the coordination structure in the CsPb(Fe)I3 perovskite crystal will improve the photovoltaic and optical properties.

Theoretical (DFT and TDDFT) insights into the effect of polycyclic aromatic hydrocarbons on Monascus pigments and its implication as a photosensitizer for dye-sensitized solar cells

Monascus pigments (MPs) as natural food pigments which have been extensively used in food industries, specifically in China, Japan, and other countries of southeastern Asian. The optoelectronic properties of the MPs with polycyclic aromatic hydrocarbons (PAHs) units have been investigated by using density functional theory (DFT) and time-dependent (TDDFT) at B3LYP and the 6-31G(d) basis set. These properties include total energies, Fermi energy, work function, orbital distributions (HOMO, LUMO), the HOMO-LUMO gap, the maximum open circuit voltage, maximum wavelength absorption, electronic transition energies, and the oscillator strengths. These methods and calculation procedures not only encourage a profound understanding of the association between the optoelectronic properties and chemical structures of the molecules but also can be utilized to design new molecule structures. We investigated the influence of the PAHs into the MPs and studied the optoelectronic properties on all molecules. The results showed that the maximum absorption wavelengths for MPs-PAHs are within the visible light region. Therefore, these molecules provide good performance for the photovoltaic devices and solar cells applications. SignificanceOur results showed that the total energy increase after addition of PAHs for MPs, this illustration that the molecules converted to more stability. The addition of PAHs can enhance HOMO, LUMO level which can upsurge reduce bandgap energy and also the faculty of electron injection. Where the bandgap energy lies in the range (2.242–3.012) eV. The λmax takes the values from 378.84 nm to 681.03 nm, where the lowest value for Ms. (S3) and highest for the Ms. (S1), where Ms. (S1) represents firsa t singlet excited state that is at about 681.03 nm but with a feeble absorption. We observed that the sturdy absorption peaks (Ms (S2), Ms-fluorene (S3), Ms-naphthalene (S3), and Ms-anthracene (S3)) are within the visible light region. These results of the dyes confirmation that these dyes are possible to be a perfect photosensitizer in solar cells.

Halide perovskite based on hydrophobic ionic liquid for stability improving and its application in high-efficient photovoltaic cell

A novel ionic liquid, 3-(3-aminopropyl)-1-methylimidazolium hexafluorophosphate (APMimPF6), with high hydrophobic property was successfully applied as the functional monomer for the halide perovskite preparation. The new hydrophobic ionic liquid significantly facilitates the perovskite forming a 2-dimensional structure with good passivation, particularly at the grain boundaries because of the high hydrophobic character and large size of ionic liquid molecule. The perovskite solar cell fabricated with this new perovskite based on the hydrophobic ionic liquid was found possessing excellent properties: the maximum value of Jsc = 22.9 mA cm−2, Voc = 1.05 V, and PCE = 17.3%. In addition, the perovskite solar cell also shows good long-term stability, which benefited from the protecting effect of the high hydrophobic ionic liquid. In a typical stability test, the cells stored under the conditions with a relative humidity of 57% for 40 days, the PCE was able to retain 98% of its initial value. Therefore, the present study demonstrated a significant protocol for the development of highly stable perovskite solar cells.