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Although various types of bifacial solar cells exist, few studies have been conducted on bifacial semitransparent CuInSe2 solar cells (BS-CISe SCs) despite the attractive potential in power generation from both sides in an albedo environment. The optimized BS-CISe SCs with 300 and 800 nm-thick absorber via a streamlined single-stage co-evaporation process exhibit a power conversion efficiency (PCE) of 6.32% and 10.6%, respectively. When double-sided total 2.0 sun illumination is assumed in an albedo environment, the bifacial power generation densities (BPGD) of them increases to 9.41% and 13.9%. Four-terminal bifacial semitransparent tandem solar cells (4T-BST SCs) are fabricated to increase the BPGD by mechanically stacking a BS-perovskite (PVK) top cell on top of a BS-CISe bottom cell with the 300 and 800 nm-thick absorber layers. When summed up, the best top and bottom cell PCEs of the 4T-BST SC with 300 and 800 nm-thick BS-CISe SC are 18.8% and 21.1%, respectively. However, the practical BPGD values of the 4T-BST SC under total 2 sun illumination are interestingly 23.4% and 24.4%, respectively. This is because the BS-CISe bottom cell's thickness affects how much rear-side illumination is transmitted to the BS-PVK top cell, increasing its current density and BPGD.
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An innovative dual-thickness semi-transparent beamstop designed to enhance the performance of small-angle X-ray scattering (SAXS) experiments is introduced. This design integrates two absorbers of differing thicknesses side by side into a single attenuator, known as a beamstop. Instead of completely stopping the direct beam, it attenuates it, allowing the SAXS detector to measure the transmitted beam through the sample. This approach achieves true synchronization in measuring both scattered and transmitted signals and effectively eliminates higher-order harmonic contributions when determining the transmission light intensity through the sample. This facilitates and optimizes signal detection and background subtraction. This contribution details the theoretical basis and practical implementation of this solution at the SAXS station on the 1W2A beamline at the Beijing Synchrotron Radiation Facility. It also anticipates its application at other SAXS stations, including that at the forthcoming High Energy Photon Source, providing an effective solution for high-precision SAXS experiments.
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The development of eco-friendly solvent-processed organic solar cells (OSCs) suitable for industrial-scale production should be now considered the imperative research. Herein, asymmetric 3-fluoropyridine (FPy) unit is used to control the aggregation and fibril network of polymer blends. Notably, terpolymer PM6(FPy = 0.2) incorporating 20% FPy in a well-known donor polymer poly[(2,6-(4,8-bis(5-(2-ethylhexyl-3-fluoro)thiophen-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione)] (PM6) can reduce the regioregularity of the polymer backbone and endow them with much-enhanced solubility in eco-friendly solvents. Accordingly, the excellent adaptability for fabricating versatile devices based on PM6(FPy = 0.2) by toluene processing is demonstrated. The resulting OSCs exhibit a high power conversion efficiency (PCE) of 16.1% (17.0% by processed with chloroform) and low batch-to-batch variation. Moreover, by controlling the donor-to-acceptor weight ratio at 0.5:1.0 and 0.25:1.0, semi-transparent OSCs (ST-OSCs) yield significant light utilization efficiencies of 3.61% and 3.67%, respectively. For large-area (1.0 cm2 ) indoor OSC (I-OSC), a high PCE of 20.6% is achieved with an appropriate energy loss of 0.61 eV under a warm white light-emitting diode (3,000 K) with the illumination of 958 lux. Finally, the long-term stability of the devices is evaluated by investigating their structure-performance-stability relationship. This work provides an effective approach to realizing eco-friendly, efficient, and stable OSCs/ST-OSCs/I-OSCs.
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Semitransparent organic photovoltaic cells (ST-OPVs) are emerging as a solution for solar energy harvesting on building facades, rooftops, and windows. However, the trade-off between power-conversion efficiency (PCE) and the average photopic transmission (APT) in color-neutral devices limits their utility as attractive, power-generating windows. A color-neutral ST-OPV is demonstrated by using a transparent indium tin oxide (ITO) anode along with a narrow energy gap nonfullerene acceptor near-infrared (NIR) absorbing cell and outcoupling (OC) coatings on the exit surface. The device exhibits PCE = 8.1 ± 0.3% and APT = 43.3 ± 1.2% that combine to achieve a light-utilization efficiency of LUE = 3.5 ± 0.1%. Commission Internationale d'eclairage chromaticity coordinates of (0.38, 0.39), a color-rendering index of 86, and a correlated color temperature of 4,143 K are obtained for simulated AM1.5 illumination transmitted through the cell. Using an ultrathin metal anode in place of ITO, we demonstrate a slightly green-tinted ST-OPV with PCE = 10.8 ± 0.5% and APT = 45.7 ± 2.1% yielding LUE = 5.0 ± 0.3% These results indicate that ST-OPVs can combine both efficiency and color neutrality in a single device.
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P-type polymers are polymeric semiconducting materials that conduct holes and have extensive applications in optoelectronics such as organic photovoltaics. Taking the advantage of intrinsic discontinuous light absorption of organic semiconductors, semitransparent organic photovoltaics (STOPVs) present compelling opportunities in various potential applications such as building-integrated photovoltaics, agrivoltaics, automobiles, and wearable electronics. The characteristics of p-type polymers, including optical, electronic, and morphological properties, determine the performance of STOPVs, and the requirements for p-type polymers differ between opaque organic photovoltaics and STOPVs. Hence, in this Minireview, recent advances of p-type polymers used in STOPVs are systematically summarized, with emphasis on the effects of chemical structures, conformation structures, and aggregation structures of p-type polymers on the performance of STOPVs. Furthermore, new design concepts and guidelines are also proposed for p-type polymers to facilitate the future development of high-performance STOPVs.
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Perovskite materials offer a great potential in the application of semitransparent solar cells, owing to the tunable bandgap, ease of preparation and excellent photovoltaic property. A majority of works exhibit high average visible-light transmittance (AVT) for semitransparent perovskite solar cells (ST-PSCs) through decreasing perovskite thickness, leading to sacrificing the power conversion efficiency (PCE) of the device. Herein, a wide-bandgap (WBG) perovskite of Cs0.2 FA0.8 Pb(I0.6 Br0.4 )3 is applied as absorber in ST-PSCs, which is a tremendous progress to balance both large PCE and high AVT. Moreover, a strategy of simultaneous interfacial modification and defect passivation is provided to enhance the performance of WBG ST-PSCs. Consequently, an inverted planar structure WBG perovskite solar cell (PSC) achieves 15.06% of PCE with excellent stability by restraining the interfacial energy loss and suppressing the nonradiative recombination. Furthermore, the ST-PSC obtains high PCE of 14.40% with an AVT of 38% by means of optimizing the transparent electrode. This work provides an efficient and simple method to improve the performance and AVT of ST-PSCs for the application in building-integrated photovoltaics.
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Compostos de Cálcio , Óxidos , Compostos de Cálcio/química , Eletrodos , Óxidos/química , Titânio/químicaRESUMO
Organic photovoltaics (OPVs) have attracted tremendous attention in the field of thin-film solar cells due to their wide range of applications, especially for semitransparent devices. Here, we synthesize a dithiaindacenone-thiophene-benzothiadiazole-thiophene alternating donor copolymer named poly{[2,7-(5,5-didecyl-5H-1,8-dithia-as-indacenone)]-alt-[5,5-(5',6'-dioctyloxy-4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)]} (PDTIDTBT), which shows a relatively wide bandgap of 1.82 eV, good mobility, and high transmittance and ambient stability. In this work, we fabricate an OPV device using monolayer graphene as top electrode. Due to the stability of PDTIDTBT in air and water, we use a wet transfer technique for graphene to fabricate semitransparent OPVs. We demonstrate OPVs based on the PDTIDTBT:Phenyl-C61/71-butyric acid methyl ester (PCBM) blend with maximum power conversion efficiencies (PCEs) of 6.1 and 4.75% using silver and graphene top electrodes, respectively. Our graphene-based device shows a high average visible transmittance (AVT) of 55%, indicating the potential of PDTIDTBT for window application and tandem devices. Therefore, we also demonstrate tandem devices using the PDTIDTBT:Phenyl-C61-butyric acid methyl ester (PC60BM) blend in both series and parallel connections with average PCEs of 7.3 and 7.95%, respectively. We also achieve a good average PCE of 8.26% with an average open circuit voltage (Voc) of 1.79 V for 2-terminal tandem OPVs using this blend. Based on tandem design, an OPV with PCE of 6.45% and AVT of 38% is demonstrated. Moreover, our devices show improved shelf life and ultraviolet (UV) stability (using CdSe/ZnS core shell quantum dots [QDs]) in ambient with 45% relative humidity.
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Low-density films of single-walled carbon nanotubes (SWNTs) can be used as a semi-transparent top electrode for all-solution-processed film devices; however, their semiconductor characteristics vary depending on the experimental factors in their dispersion into solvents, and the sublayers are damaged as a result of solvent incompatibility. In this study, we report a solvent-compatible filter-transfer method for SWNT films stacked with silver nanowires (AgNWs), and evaluate the semiconductor characteristics through the p/n heterojunction with a Si wafer (SWNT/Si). AgNWs and SWNTs were successively filtered through their aqueous dispersion solutions using a membrane filter. The stacked semi-transparent films (AgNW/SWNT films with controlled densities) were successfully transferred onto glass plates and Si wafers. The transmittance at 550 nm revealed a window between 60% and 80% with a narrow sheet resistance range between 11 and 23 Ω â¡-1. The power conversion efficiency (PCE) of SWNT/Si was improved to 11.2% in a junction area of 0.031 cm2 through the use of spin-coated Nafion resins; however, the accumulated resistance of SWNTs drastically reduced the PCE to 2% as the area increased to ≥0.5 cm2. AgNWs maintained the PCE within a range of 10.7% to 8.6% for an area ranging from 0.031 cm2 to 1.13 cm2. All of the photovoltaic parameters were dependent on the junction areas, suggesting that AgNWs function as an effective current-collector layer on the semiconductor layer of SWNTs without direct contact of AgNWs with the Si surface. In addition, we report a solvent-compatible experiment for transferring AgNW/SWNT films onto a solvent-sensitive perovskite material (CH3NH3PbI3).
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There has been a surge in the interest for (semi)transparent photovoltaics (sTPVs) in recent years, since the more traditional, opaque, devices are not ideally suited for a variety of innovative applications spanning from smart and self-powered windows for buildings to those for vehicle integration. Additional requirements for these photovoltaic applications are a high conversion efficiency (despite the necessary compromise to achieve a degree of transparency) and an aesthetically pleasing design. One potential realm to explore in the attempt to meet such challenges is the biological world, where evolution has led to highly efficient and fascinating light-management structures. In this mini-review, we explore some of the biomimetic approaches that can be used to improve both transparent and semi-transparent photovoltaic cells, such as moth-eye inspired structures for improved performance and stability or tunable, coloured, and semi-transparent devices inspired by beetles' cuticles. Lastly, we briefly discuss possible future developments for bio-inspired and potentially bio-compatible sTPVs.
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Biomimética , Animais , BesourosRESUMO
Semitransparent organic solar cells (ST-OSCs) are considered as one of the most valuable applications of OSCs and a strong contender in the market. However, the optical band gap of current high-performance ST-OSCs is still not low enough to achieve the optimal balance between power conversion efficiency (PCE) and average visible transmittance (AVT). An N-substituted asymmetric nonfullerene acceptor SN with over 40â nm bathochromically shifted absorption compared to Y6 was designed and synthesized, based on which the device with PM6 as donor obtained a PCE of 14.3 %, accompanied with a nonradiative voltage loss as low as 0.15â eV. Meanwhile, ternary devices with the addition of SN into PM6 : Y6 can achieve a PCE of 17.5 % with an unchanged open-circuit voltage and improved short-circuit current. Benefiting from extended NIR absorption and lowered voltage loss, ST-OSCs based on PM6 : SN : Y6 were fabricated and the optimized device demonstrated a PCE of 14.0 % at an AVT of 20.2 %, which is the highest PCE at an AVT over 20 %.
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The present study reported an experiment examining whether both native speakers (NSs) and non-native speakers (NNSs) give formulaic sequences (FSs) priority over novel phrases in processing, as the dual route model has postulated. In this experiment, NSs and NNSs were asked to read Japanese versions of semi-transparent restricted collocations (e.g., kenka-o uru 'pick a fight (acc)'), novel phrases (e.g., tomato-o uru 'sell tomatoes (acc)'), and violated phrases (e.g., kenka-o sagasu 'find out a fight (acc)'); and they judged the naturalness of these sequences. Participants' reaction times were measured, as well as their cortical activation. The results revealed that, for the NSs, collocations required shorter reaction times and elicited less cortical activation than the novel stimuli. For NNSs, collocations similarly required shorter reaction times, but they elicited greater cortical activation than novel phrases. These results support the dual route model, both for NSs and NNSs.
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Leitura , Espectroscopia de Luz Próxima ao Infravermelho , HumanosRESUMO
We investigated the characteristics of thermally evaporated fullerene (C60)/Ag/C60 (CAC) multilayer films for use in semi-transparent perovskite solar cells (PSCs) and thin-film heaters (TFHs). The top and bottom C60 layers and Ag interlayer were prepared using multi-source thermal evaporation, and the thickness of the Ag interlayer was investigated in detail for its effects on the resistivity, optical transmittance, and mechanical properties of the CAC electrodes. We used a figure-of-merit analysis to obtain a CAC electrode with a smooth surface morphology that exhibited a sheet resistance of 5.63 Ohm/square and an optical transmittance of 66.13% at a 550 nm wavelength. We conducted mechanical deformation tests to confirm that the thermally evaporated multilayer CAC electrode has a high durability, even after 10,000 times of inner and outer bending, rolling, and twisting due to the flexibility of the amorphous C60 and Ag interlayer. We evaluated the feasibility of using CAC electrodes for semi-transparent PSCs and TFHs. The semi-transparent PSC with 1.08 cm2 active area prepared with a transparent multilayer CAC cathode showed a power conversion efficiency (PCE) of 5.1%. Furthermore, flexible TFHs (2.5 × 2.5 cm2) fabricated on a thermally evaporated CAC electrode show a high saturation temperature of 116.6 C, even at a low input voltage of 4.5 V, due to a very low sheet resistance. Based on the performance of the PSCs and TFHs, we conclude that the thermally evaporated multilayer CAC electrode is promising for use as a transparent conductive electrode (TCE) for semi-transparent PSCs and TFHs, with characteristics comparable to sputtered TCEs.
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In this research, due to the present pandemic of COVID-19, we are proposing a stable and fixed semitransparent photo-thermoelectric cell (PTEC) module for green energy harvesting. This module is based on the alloy of Bismuth Telluride Selenide (Bi2Te3Se), designed in a press tablet form and characterized under solar energy. Here, both aspects of solar energy i.e., light and heat are utilized for both energy production and water heating. The semitransparent PTEC converts heat energy directly to electrical energy due to the gradient of temperature between two electrodes (top and bottom) of thermoelectric cells. The PTEC is 25% transparent, which can be varied according to the necessity of the utilizer. The X-ray diffraction of material and electric characterization of module i.e., open-circuited voltage (VOC) and Seebeck coefficient were performed. The experimental observations disclose that in the proposed PTEC module with an increment in the average temperature (TAvg) from 34 to 60 °C, results in the rise of VOC â¼ 2.4 times. However, by modifying the size of heat-absorbing top electrode and by increasing the temperature gradient through the addition of water coolant under the bottom electrode, an uplift in the champion device results in as increment of VOC â¼5.5 times and Seebeck coefficient obtained was -250 µV/0C, respectively. Results show that not only the selection of material but also the external modifications in the device highly effective the power efficiency of the devices. The proposed modules can generate electric power from light and utilize the penetrating sunlight inside the room and for the heating of the water which also acts as a coolant. These semitransparent thermoelectric cells can be built-in within windows and roofs of buildings and can potentially contribute to green energy harvesting, in situations where movement is restricted locally or globally.
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Organic-inorganic hybrid perovskites have been investigated extensively for use in perovskite-based solar cells and light-emitting diodes (LEDs) because of their excellent electrical and optical properties. Although the flexibility of perovskite LEDs has been studied through empirical methods such as cyclic bending tests, the flexibility of the perovskite layer has not been investigated systemically. Here, flexible and semitransparent perovskite LEDs are fabricated: a PEDOT:PSS anode and Ag nanowire cathode allow for flexible and semitransparent devices, while the use of a conjugated polyelectrolyte as an interfacial layer reduces the electron injection barrier between the cathode and the electron transport layer (SPW-111), resulting in enhanced device efficiency. Cyclic bending tests performed on the electrodes and in situ hole-nanoindentation tests performed on the constituent materials suggest that mechanical failure occurs in the perovskite MAPbBr3 layer during cyclic bending, leading to a decrease in the luminance. Tensile properties of the MAPbBr3 layer explain the critical bending radius ( rb) of the perovskite LEDs on the order of 1 mm.
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Chiral materials with circularly polarized luminescence (CPL) are potentially applicable for 3D displays. In this study, by decorating the pyridinyl-helicene ligands with -CF3 and -F groups, the platinahelicene enantiomers featured superior configurational stability, as well as high sublimation yield (>90 %) and clear CPPL properties, with dissymmetry factors (|gPL |) of approximately 3.7×10-3 in solution and about 4.1×10-3 in doped film. The evaporated circularly polarized phosphorescent organic light-emitting diodes (CP-PhOLEDs) with two enantiomers as emitters exhibited symmetric CPEL signals with |gEL | of (1.1-1.6)×10-3 and decent device performances, achieving a maximum brightness of 11 590â cd m-2 , a maximum external quantum efficiency up to 18.81 %, which are the highest values among the reported devices based on chiral phosphorescent PtII complexes. To suppress the effect of reverse CPEL signal from the cathode reflection, the further implementation of semitransparent aluminum/silver cathode successfully boosts up the |gEL | by over threeâ times to 5.1×10-3 .
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The morphology of hybrid organic-inorganic perovskite films is known to strongly affect the performance of perovskite-based solar cells. CH3 NH3 PbI3-x Clx (MAPbI3-x Clx ) films have been previously fabricated with 100% surface coverage in glove boxes. In ambient air, fabrication generally relies on solvent engineering to obtain compact films. In contrast, this work explores the potential of altering the perovskites microstructure for solar cell engineering. This work starts with CH3 NH3 PbI3-x Clx , films with grain morphology carefully controlled by varying the deposition speed during the spin-coating process to fabricate efficient and partially transparent solar cells. Devices produced with a CH3 NH3 PbI3-x Clx film and a compact thick top gold electrode reach a maximum efficiency of 10.2% but display a large photocurrent hysteresis. As it is demonstrated, the introduction of different concentrations of bromide in the precursor solution addresses the hysteresis issues and turns the film morphology into a partially transparent interconnected network of 1D microstructures. This approach leads to semitransparent solar cells with negligible hysteresis and efficiencies up to 7.2%, while allowing average transmission of 17% across the visible spectrum. This work demonstrates that the optimization of the perovskites composition can mitigate the hysteresis effects commonly attributed to the charge trapping within the perovskite film.
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Controlled nucleation and growth of metal clusters in metal deposition processes is a long-standing issue for thin-film-based electronic devices. When metal atoms are deposited on solid surfaces, unintended defects sites always lead to a heterogeneous nucleation, resulting in a spatially nonuniform nucleation with irregular growth rates for individual nuclei, resulting in a rough film that requires a thicker film to be deposited to reach the percolation threshold. In the present study, it is shown that substrate-supported graphene promotes the lateral 2D growth of metal atoms on the graphene. Transmission electron microscopy reveals that 2D metallic single crystals are grown epitaxially on supported graphene surfaces while a pristine graphene layer hardly yields any metal nucleation. A surface energy barrier calculation based on density functional theory predicts a suppression of diffusion of metal atoms on electronically perturbed graphene (supported graphene). 2D single Au crystals grown on supported graphene surfaces exhibit unusual near-infrared plasmonic resonance, and the unique 2D growth of metal crystals and self-healing nature of graphene lead to the formation of ultrathin, semitransparent, and biodegradable metallic thin films that could be utilized in various biomedical applications.
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In many optoelectronic applications, patterning is required for functional and/or aesthetic purposes. However, established photolithographic technique cannot be applied directly to the hybrid perovskites, which are considered as promising candidates for optoelectronic applications. In this work, a wettability-assisted photolithography (WAP) process, which employs photolithography and one-step solution process to deposit hybrid perovskite, was developed for fabricating patterned hybrid perovskite films. Uniform pinhole-free hybrid perovskite films with sharp-edged micropatterns of any shapes can be constructed through the WAP process. Semitransparent solar cells with an adjustable active layer average visible transmittance of a wide range from 20.0% to 100% and regular solar cells based on patterned CH3NH3PbI3 perovskite films were fabricated to demonstrate that the WAP process was compatible with the manufacturing process of optoelectronic devices. With the widely equipped photolithographic facilities in the modern semiconductor industry, we believe the WAP process have a great potential in the industrial production of functionally or aesthetically patterned hybrid perovskite devices.
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Recently, deoxyribonucleic acid (DNA) is studied for electronics due to its intrinsic benefits such as its natural plenitude, biodegradability, biofunctionality, and low-cost. However, its applications are limited to passive components because of inherent insulating properties. In this report, a metal-insulator-metal tunnel diode with Au/DNA/NiOx junctions is presented. Through the self-aligning process of DNA molecules, a 2D DNA nanosheet is synthesized and used as a tunneling barrier, and semitransparent conducting oxide (NiOx ) is applied as a top electrode for resolving metal penetration issues. This molecular device successfully operates as a nonresonant tunneling diode, and temperature-variable current-voltage analysis proves that Fowler-Nordheim tunneling is a dominant conduction mechanism at the junctions. DNA-based tunneling devices appear to be promising prototypes for nanoelectronics using biomolecules.
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DNA/química , Eletricidade , Eletrônica , Sequência de Bases , TermodinâmicaRESUMO
Indirect focusing of the output from a pulsed infrared Nd3+ :YAG laser through a shock-generating layer onto organic crystals results in the emission of an intense microsecond duration pulse of mechanoluminescence (ML). The ML appears after a threshold laser fluence has been reached and increases sharply above this threshold. This specifies that there is a corresponding amplitude of a laser-induced shock wave that is necessary to induce crystal fracturing. Thus, the intensity of ML can be controlled by varying the laser fluence. Piezoelectric charges produced on the surfaces of a fractured crystal create the foundation for luminescence. Initially, the ML intensity increases with the shock wave pressure and time due to the creation of more surfaces in the crystal; the ML intensity reaches a peak value and then decreases over time. Thus, laser shock wave-induced ML provides a new optical technique for the study of materials under high pressure. Expressions explored for the characteristics of laser shock wave-induced ML satisfactorily explain the experimental results. Copyright © 2016 John Wiley & Sons, Ltd.