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A simple, air processable, DMF molecular ink-based process is presented through which it was able to achieve a new certified record efficiency of 14.4% for the low-gap CuIn(S,Se)2 device.

Summary The charge transferability of the electron transfer layers (ETLs) is important for achieving high performance in mesoscopic (mp) perovskite solar cells (PSCs). However, because of the low electron extraction efficiency of TiO2, lithium doping is essentially required. In this work, we compared the electrical properties of mp-TiO2 doped with Li-salts with different anions—LiTFSI, Li2CO3, LiCl, and LiF. Interestingly, we found that the anions of the Li-salt dopants affect the electrical properties of the ETLs and the solar cell performance. The Li2CO3 doping of mp-TiO2 led to conduction bands deeper than those of pristine mp-TiO2 or other doped mp-TiO2. The maximum efficiency of 25.28% and certified efficiency of 24.68% (Newport) was obtained by using Li2CO3 dopant. This optimization of the ETLs properties is expected to greatly contribute to the progress of PSCs by leading to further increases in their efficiency.

Multiwalled carbon nanotubes (MWCNTs) are at the forefront of metal-free electrocatalysts, however, the performance is still limited due to lack of functionality and dispersion. Coupling of MWCNTs with nitrogen doped carbon quantum dots (NCQDs) can impart the required active sites and dispersion. For the purpose, NCQDs are generally attached to MWCNTs by multistep processing, such as NCQDs synthesis, followed by their complex purification, surface activation, and crosslinking with MWCNT. The scalability of such a multistep process is limited, which is addressed by direct microwave-assisted growth of NCQDs on MWCNT. The concentration of reactants of NCQDs synthesis was optimized (with respect to MWCNTs), to achieve controlled direct growth of NCQDs on MWCNTs. The proposed strategy significantly reduced time and energy consumption, along with providing an overlapped interface for the fast charge transfer. Moreover, NCQDs' growth effectively modulated the surface reactivity and internal band structure of the MWCNTs. In response, dye-sensitized solar cells employing NCQDs modified MWCNT as a counter electrode showed 50% higher photovoltaic performance as compared to bare MWCNTs.

In this study, a photovoltaic system with RETScreen software is simulated to see its economic and environmental feasibility in the one of the remote locations in Pakistan. Our proposed photovoltaics power system is installed south Asia: particularly, Pakistan which receives a high amount of solar irradiance throughout the year. The proposed location has an electricity demand of 28.70 MWh/month, and our simulated PV system generates 31 MWh/month which is more than the amount of required electricity demand. The 25 years long life project will have energy payback time of 7.4 years and the net greenhouse gas (GHG) emission reduction will be 3,942 tCO2 for the whole project life. These results summarize that installation of this solar power system is not only economically feasible, but also reduces the emission of greenhouse gases in that selected location.

The defects present in solution-processed perovskite light absorbing materials are responsible for deteriorating the performance and stability of perovskite solar cells. Therefore, suppressing the defect formation and passivating the pre-existing defects in perovskite materials are of paramount importance in pushing the efficiency of perovskite solar cells (PSCs) toward the theoretical limit and ensuring the long-term stability of PSCs. In this work, we report an efficient defect passivation route using a bidentate small organic molecule, pyrazine, which is capable of making either a monodentate or a bridging bidentate bond with under-coordinated Pb2+ ions mainly present in the surface and grain boundaries of perovskite films. The various analyses for the defect density and charge carrier lifetime of perovskite light absorbing layers demonstrated that pyrazine effectively passivated defects existing on the surface and grain boundaries of the perovskite films without affecting the morphology and crystallinity via a simple post-treatment procedure. As a result, the best untreated device obtained a power conversion efficiency of 19.14%, while an efficiency of 20.58% was achieved when pyrazine treated.

As an alternative buffer material to CdS, ZnxCd1-xS buffer layers for vapor transport-deposited SnS thin-film solar cells (TFSCs) were fabricated using the successive ionic layer adsorption and reaction (SILAR) method. Varying the Zn-to-Cd ratio resulted in a series of ZnxCd1-xS thin films with controllable band gaps in the range of 2.40-3.65 eV. The influence of the Zn-to-Cd ratio on the cell performance was investigated in detail. The Zn0.34Cd0.66S buffer layer was found to be the optimal composition for SnS TFSCs, and a record open-circuit voltage (Voc) of 0.405 V was achieved with an efficiency of 3.72%, whereas the SILAR-CdS buffer layer rendered a Voc of 0.324 V. The improvement in Voc when using the Zn0.34Cd0.66S buffer layer was corroborated by the spike-type conduction band offset of 0.35 eV with the SnS absorber, as revealed by the X-ray photoelectron spectroscopy analysis. In addition, minimized interfacial recombination at the SnS/Zn0.34Cd0.66S heterojunction was confirmed by the temperature-dependent Voc analysis under illuminated conditions.

Control of the constituent phase and stoichiometry of iron pyrite (FeS2) is a prerequisite for high-performance photovoltaic devices based on this material. If the pyrite contains sulfur-deficiency-related secondary phases which have a metallic character and a high possibility of coexistence in pyrite films, then significant carrier recombination is expected. In this work, the beneficial role of Na in suppressing the formation of nanoscale or amorphous sulfur-deficient secondary phases is reported with experimental evidence, leading to a higher phase purity for solution-processed pyrite films. The potential reduction of charge recombination via these metallic secondary phases results in significant improvements in both the photopotential and photocurrent intensity of Na-modified pyrite films compared with reference samples.

Cu(In,Ga)Se2 (CIGSe) solar cells with absorber thicknesses of

Thinning CIGSe absorber layer to less than 500 nm is desirable for reducing the cost per unit watt of photovoltaic-generated electricity, and also, the semitransparent solar cell based on such a thin absorber can be used in bifacial and superstrate configurations if the back electrode is transparent. In this study, a WO x layer is inserted between Cu(In,Ga)Se2 (CIGSe) absorber and tin-doped indium oxide back-contact to enhance the hole collection at the back electrode. A WO x interlayer with a thickness of 6 nm is found to be optimum because it causes a ∼38% relative increase in the fill factor of a ∼450 nm thick CIGSe-based device compared to the reference device without a WO x interlayer. While fixing the thickness of CIGSe, increasing the WO x interlayer thickness to ≥6 nm results in decreases of solar cell parameters primarily because of the emergence of a GaO x interfacial layer at the CIGSe/WO x junction.

BACKGROUND Honey is a natural product used as food, medicine, or cosmetics for very long time and is made by bees. Honey contains various components such as sugar, protein, minerals, and vitamins. Honey is made by Apis cerana or Apis mellifera , which commonly has major royal jelly proteins (MRJP s) as a major protein. To discriminate between natural honey (NH ) and artificial honey (AH ), many researchers tried method of physicochemical analysis. However, the analysis results were ambiguous and not stable. RESULTS We have produced a monoclonal antibody that recognizes MRJP s of honeys in common. Monoclonal antibody has advantage such as accuracy, sensitivity, and stability as the standard. The specificity and affinity of produced antibody were measured by western blotting and enzyme‐linked immunosorbent assay. As a result, this monoclonal antibody specifically recognized MRJP s of NH and did not recognize AH which has not including MRJP s. CONCLUSION Natural honey could be able to distinguish from AH accurately by using this monoclonal antibody. Also, this method could be commercially applicable.

Tin monosulfide (SnS) thin film is one of the most promising absorbers layer for high efficiency solar cells using low cost earth-abundant materials. To fabricate high quality SnS thin films, a simple nanoparticle based approach was employed in this work for phase pure material preparation using non-toxic solvents. Uniform SnS thin films were fabricated via a spin-coating process using phase pure SnS-ORT nanoparticle precursor solutions based on a methanol solvent, followed by post-annealing for grain growth. SnS thin film solar cells were then fabricated and their photovoltaic performance was characterized. The best SnS solar cell fabricated with the as-prepared SnS films with a band gap energy of ~1.25 eV showed a conversion efficiency of 0.12%.

As an alternative buffer material to CdS, Zn

Na has been believed to improve the device parameters of open circuit voltage (VOC) and fill factor (FF) presumably by increasing the carrier concentration (NA) of vacuum-processed Cu(In,Ga)Se2 films. In solution-processed CI(G)Se devices as well, Na reportedly increases VOC and FF but this improvement is not correlated with the increase in NA, suggesting a different physical mechanism associated with Na in solution-based routes. In this contribution, experimental results on the role of Na addition in solution-processed CISe films and devices were reported, in which Na addition had no influence on NA nor on film composition in spite of the notable increase in the device efficiency. On the contrary, Na was found to mitigate the interfacial recombination by reducing the undesirable surface defects. Along with this understanding, Na addition in our air-processable route resulted in a CISe device with 12.83% efficiency, which is comparable to the current world record efficiency of solution-processed CISe devices.

The structural and electro-optical influence of marcasite on the properties of solution-processed iron pyrite thin films was investigated. Marcasite has a strong tendency to form simultaneously with pyrite upon sulfurization of amorphous iron-oxide precursor films, leading to a mixed-phase structure in which pyrite grains are surrounded by nanocrystalline marcasite boundaries. The optical analysis in combination with spectroscopic ellipsometry revealed that marcasite should have a bandgap of approximately 0.85–0.88 eV with a higher absorption coefficient than pyrite, differing strongly from the prior belief that marcasite has a bandgap of less than 0.4 eV. In addition, the pyrite/marcasite film has been found to have a larger diffusion coefficient for photogenerated minority carriers than the phase-pure pyrite film from electrochemical impedance analyses, resulting in a higher photocurrent density, as determined through photoelectrochemical measurement. The facile transport of a minority carrier along the marcasite boundaries is the putative origin of the observed improvement in the photoactivity of the pyrite/marcasite mixture films.

Tin monosulfide (SnS) is an earth-abundant semiconductor material and shows potential as an absorber for solar cells. However, it is difficult to obtain the pure SnS phase because other binary phases of Sn-S (SnS 2 , Sn 2 S 3 and Sn 3 S 4 ) are more favorable in air. In this report, solution and liquid precursors were used to fabricate pure SnS thin films on Mo-coated soda lime glass using a direct solution coating method and subsequent annealing at different reaction temperatures. Direct solution coating is an easy and rapid process for large-scale fabrication. Additionally, it allows for precise control of the thin film stoichiometry. The phase and morphology of the fabricated SnS thin films were confirmed by XRD, XPS, Raman and SEM. The films prepared using the solution precursor showed additional phases along with SnS. However, for the films prepared with the liquid precursor, only the SnS orthorhombic structure was observed.

We demonstrate production of high-quality Cu(InGa)(SSe) 2 (CIGSSe) films by high-rate supersonic spray deposition. This technique is unique in creating particle-based films without introducing impurities, because no additives or binders are used. The thin film deposition process was investigated computationally, to understand the pulverization of the incoming particles. These simulations were consistent with experimental observations. Grain growth was improved by adding a 300-nm copper layer atop the CIGSSe film; selenization of the resulting bilayer produced a CuSe liquid flux that assisted the sintering process. The final CIGSSe film-based solar cell had a conversion efficiency of 5.49% with J sc = 18.73 mA/cm 2 , V oc = 0.488 V, and FF = 59.99% in an active area of 0.44 cm 2 .

An amorphous Cu–In–S nanoparticle-based precursor ink with improved atom economy was developed in which a large amount of bulky organic ligands was replaced with metal salt–organic ligand complexes. This change resulted in a reduction of the required amount of organic ligands in the ink, meaning that additional spaces in the green layer were occupied by constituent metal atoms rather than organic ligands. Using modified amorphous Cu–In–S nanoparticle inks containing metal salt–organic ligand complexes, improvement of the morphologies of selenized CuInSe2 thin films was observed in terms of greater compactness, better flatness, and larger grains, which led to an increase in the device efficiency to 10.85%. This result demonstrates that even with low-quality precursor materials, such as amorphous Cu–In–S nanoparticles, proper control of the atom economy of the precursor inks enables the facile fabrication of high-quality inorganic semiconductor films and devices at low cost.

Photoelectrochemical (PEC) water splitting was performed using co-evaporated Cu(In,Ga)Se 2 (CIGS, p-type) films as the photocathode. Pt was electrodeposited on CIGS and CIGS/CdS films. The effect of the electrodeposition time was investigated to determine the optimal deposition conditions. The CIGS film was covered with a 60-nm-thick CdS layer (n-type) using a chemical-bath deposition technique, which created a p-n junction. The effect of the Pt electroplating time was again investigated for the CIGS/CdS films; thus, the effect of CdS addition could be quantitatively investigated. The effect of the pH of 0.5 M Na 2 SO 4 electrolyte was also investigated. The optimal water-splitting performance occurred at −24.16 mA/cm 2 at −0.7 V vs. Ag/AgCl with a Pt electrodeposition time of 20 min and pH 9. The CIGS/CdS films were characterized by X-ray diffraction, scanning electron microscopy, and focused-ion beam transmission electron microscopy.

A solar cell based on Cu(In 1−x ,Ga x )Se 2 (CIGS) with bandgap (E g ) of 1.5 eV is superior because of the low coefficient of power loss and resistive losses. CIGS thin-films with the E g = 1.5 eV and Cu/(Ga + In) (CGI) ratios of 0.92, 0.84, and 0.78 were deposited in this study using single-stage process. Photovoltaic (PV) parameters of the solar cell ameliorated on raising CGI values from 0.78 to 0.84, but abruptly deteriorated on further increasing the CGI value to 0.92. The PV properties of CIGS solar cell with CGI = 0.92 were poor due to the high defect density and low shunt resistance. The optimal CGI range for making efficient wide gap CIGS solar cells through the single-stage process was found to be from ∼0.80 to 0.84. The best CIGS solar cell with CGI value of 0.84 exhibited the conversion efficiency of 11.00%.

Control of the constituent phase and stoichiometry of iron pyrite (FeS

Thinning CIGSe absorber layer to less than 500 nm is desirable for reducing the cost per unit watt of photovoltaic-generated electricity, and also, the semitransparent solar cell based on such a thin absorber can be used in bifacial and superstrate configurations if the back electrode is transparent. In this study, a WO

High-performance cascaded-junction quantum dot solar cells (CJQDSCs) are fabricated from as-prepared highly monodispersed lead sulfide QDs. The cells have a high power conversion of 9.05% and a short-circuit current density of 32.51 mA cm-2. A reliable and effective stratagem for fabricating high-quality lead sulfide quantum dots (QD) is explored through a "monomer" concentration-controlled experiment. Robust QDSC performances with different band gaps are demonstrated from the as-proposed synthesis and processing stratagems. Various potential CJQDSCs can be envisioned from the band edge evolution of the QDs as a function of size and ligands reported here.

Ethnopharmacological relevance The dried rhizome of Coptis chinensis Franch. (Huanglian) has been widely used in Asian traditional medicine. It was already known that Coptis chinensis Franch. rhizome has various pharmacological properties including its anti-oxidant, anti-cancer, and anti-inflammatory activity. Aim of the study To evaluate the immune-enhancement effect of the Coptis chinensis Franch. rhizome extract on helper T cells and its signaling mechanism. Materials and methods MOLT-4 human T cell line was used to investigate the effect of the Coptis chinensis Franch. rhizome extract. Cell viability was measured by the MTT assay and cytokine expression level was analyzed by ELISA and qRTPCR. MAPKs signal molecule’s activation level was detected by immunoblotting. Results The expression of IFN-γ, a cytokine of type I helper T (Th1) cell, increased; however, IL-4 was not affected by the Coptis chinensis Franch. rhizome extract. Other Th1 cytokines, such as IL-1β, IL-2, and IL-6, also increased. These data suggest that the Coptis chinensis Franch. rhizome extract activates MOLT-4 cell to Th1 cell, not type II helper T cell. Furthermore, the Coptis chinensis Franch. rhizome extract activates the Mitogen-activated protein kinase (MAPKs) signaling pathways. Conclusion The results obtained from this study suggest that the Coptis chinensis Franch. rhizome extract should be used as an immune enhancer in anti-inflammatory medicine, adjuvant materials, and as a supplement to treat weakened immune system.

The temperature variation of solar cells due to white bias light irradiation during the spectral responsivity measurement and its effect on the spectral responsivity measurement result were investigated for various types of solar cells, such as crystalline silicon (c-Si), Cu(In,Ga)Se 2 (CIGS), and dye-sensitized solar cells (DSSCs). For the investigation, a spectral responsivity measurement system, which can employ the well-known sample temperature control methods (such as the “temperature controlled sample stage” method and the “forced air cooling” method) has been used. Hence, the availability of these sample temperature control methods has also been tested. Through the investigation, it was found that the actual temperature of the solar cells located under the AM1.5G-approximated white bias light can be increased significantly during the spectral responsivity measurement, depending on the sample temperature control methods applied. In addition, it was also found that the increase of sample temperature can lead to a significant error in the measured spectral responsivity, depending on the types of solar cells being measured. In addition, a simple analytic model based on the classical heat transfer theory was developed to understand the temperature variation of the solar cells under the spectral responsivity measurement environment.

CuSbS 2 (CAS) thin films were fabricated by non-toxic, low-cost and simple non-vacuum methods using hybrid inks, which is a well-known method for fabricating CuInSe 2 (CIS) films. Hybrid inks with and without nanoparticles were both tested. CAS thin films were formed on Mo-coated soda lime glass through the sulfurization of spin-coated, as-deposited films. After sulfurization, EDS, XRD, and SEM were used to analyze film composition, crystal structure and morphology. Synthesized Cu–S binary nanoparticles were used in the hybrid ink containing nanoparticles. However, Sb 2 S 3 was formed as a by-product with CuSbS 2 after sulfurization. On the other hand, for the hybrid ink containing no nanoparticles, only the CuSbS 2 phase was obtained, which enhanced the photovoltaic performance of the cell. The highest conversion efficiency of the fabricated device using the structure Mo/CuSbS 2 /CdS/i-ZnO/n-ZnO/Al was 3.22%.

In this study, we characterized FeS2 thin films grown by the non-vacuum spin-coating method. We annealed the samples under a sulfur atmosphere at different sulfurization temperatures. The phase transformation from marcasite-containing pyrite to pure pyrite occurs between 350 and 400 °C. The structural phase formation on the films depends on the sulfurization temperature. It is known that pure pyrite thin films are more suitable for solar cells. FeS2 thin films with and without the marcasite phase were investigated in terms of their local electrical properties and carrier transport by conductive atomic force microscopy and Kelvin probe force microscopy. Interestingly, the pure pyrite thin film shows less conducting behavior than the mixed phase sample because the mixed phase thin film has other residues on the surface. Pure pyrite shows two major work functions at 4.64 and 4.70 eV, and the mixed phase sample has multiple surface potential peaks below 4.63 eV, which is the main pyrite FeS2 work function. Pure-phase pyrite thin films are promising for earth-abundant solar cell applications.

Different from conventional photovoltaics, building-integrated photovoltaics needs not only high performance but also a high degree of transparency. Nevertheless, the Cu(In,Ga)Se2 (CIGS) solar cell has advantages in terms of the highest conversion efficiency and stability among all thin-film-based solar cells. The semitransparent (ST) CIGS solar cell using an ultrathin CIGS absorber on a transparent conducting oxide (TCO) experiences loss in fill factor and open circuit voltage due to the poor grain morphology and CIGS/TCO interface. Thus, these issues must be addressed to realize ST CIGS solar cells. Wide-bandgap (1.5 eV) submicron CIGS-based solar cells were prepared in this study unlike conventional CIGS with a bandgap of 1.2 eV, in order to enhance see-throughness. But such cells demonstrated low conversion efficiency due to the poor grain morphology and absence of back grading. Therefore, for the sake of improving grain morphology and to create back grading, a sulfurized-AgGa (AGS) layer was deposited between CIGS and the indium tin oxide (ITO) back contact. Ag from the AGS layer diffused throughout the absorber and thus ameliorated the grain morphology. However, Ga and S in the AGS layer remained confined near the back contact, therefore resulting in the creation of back grading. Consequently, a solar cell based on 230 nm thick CIGS modified with a 45 nm thick AGS layer exhibited efficiency of 5.94% with averaged visible transmittance over 25%. This is the highest reported efficiency for a ST CIGS solar cell with over 20% visible transparency. The CIGS solar cell based on this novel approach can be a competent candidate for building-integrated semitransparent photovoltaics applications.

One of the most important experimental factors in selenization, in which a precursor material is annealed at high temperature with Se vapor or gas to form chalcogenide light-absorbing layers, is the partial pressure of the Se vapor or gas (PSe). Although it is generally believed that the PSe should be sufficient to induce enhanced grain growth in the final film, the quantitative estimation of PSe has rarely been reported, and a detailed physical understanding of how the characteristics of absorber films and corresponding devices are affected by PSe is still far from clear. We performed a systematic study to address these PSe-related issues on solution processed CISe2 (CISe) thin films and solar cells. Based on a gas pressure equilibration model, we quantitatively estimated the actual PSe value and used this model to gain insight into how the initial experimental conditions of the Se level or background pressure influenced the actual PSe. It was found that the actual PSe varied significantly differently in an unexpected way: PSe did not vary linearly with the initial amount of Se and the trend of variation was significantly affected by the background pressure. The device parameter of the solution processed CISe solar cells that was primarily affected by PSe was the shunting, which is interpreted by the morphological differences of the absorber films grown under different PSe conditions.