Crystalline Cis Research Articles

Physical properties of highly crystalline CIS layer prepared using single phase electrodeposition and low temperature RTP annealing

CuInSe2 nanoparticles (CIS-NP) were synthesized on ITO-coated glass substrate by electrodeposition and rapid thermal processing (RTP). The as-deposited films were annealed under argon atmosphere at 250 °C, 350 °C and 450 °C using RTP during a short annealing time. The latter is practicable to avoid further losing of the Se content in CIS films. In order to analyze the effect of annealing temperature, the structural, morphological, optical and electrical properties were investigated by means of X-ray diffraction, scanning electron microscopy, UV–Visible Spectroscopy and Mott-Schottky plots respectively. XRD results show that elaborated films have a tetragonal chalcopyrite CIS with preferential orientation along the (112) orientation. The phase formation of CIS-NP with good crystallinity was observed at low annealing temperature. Optical absorption studies indicate a direct band gap around 1.02 eV at 250 °C. The optical constants such as refractive index n(λ) and extinction coefficient k(λ) were estimated using an appropriate optical model. To determine the doping type of elaborated semiconductor, its flat band potential and the free carrier concentration we used the Mott-Schottky plots. A new attempt to anneal the electrodeposited CIS films by short annealing duration using RTP process was proved to be a useful method to synthesize polycrystalline CIS films for solar cell application.

Phase Transformation of Se/(Cu,In,Ga)/Mo/Glass Thin Films: A Real-Time Synchrotron X-ray Scattering Study.

The phase transformation of Se/(Cu,In,Ga)/Mo/glass thin films during annealing in a vacuum on and off state was studied in a real-time synchrotron X-ray scattering experiment. The crystalline CIGS phase is a solid solution of crystalline CIS and CGS phases. The crystalline CIS phase was formed first at lower temperature. By increasing the temperature, the crystalline CIS phase disappeared, while the crystalline Ga2Se3, In2Se3, Cu2In phases grew simultaneously. Finally, the crystalline CIGS phase was formed at higher temperature, while the crystalline Ga2Se3, In2Se3, Cu2In phases disappeared gradually. The behavior of the crystal domain sizes was consistent with the changes of X-ray powder diffraction profiles. The high crystallization temperature of the CIGS phase was attributed to the activation energy barrier for the diffusion of Ga ions into the intermediate CIS phase.

Thermodynamic properties of 1,2-cyclohexanediols

The enthalpy values for the combustion and formation of crystalline cis and trans-1,2-cyclohexanediols are determined via bomb calorimetry. The vapor pressures of the compounds and their enthalpies of sublimation are measured. Using quantum-chemical methods, the reliability of the experimental data is estimated, the molecular structures of the compounds are studied, and the structures of the most stable conformers are established. The energy values of the intramolecular hydrogen bonds in the diol molecules are found.

Stereospecific Synthesis of Substituted Aziridines by a Crystal-to-Crystal Photodenitrogenation of Δ2-1,2,3-Triazolines

Crystalline cis- or trans-Δ(2)-1,2,3-triazolines prepared by highly stereospecific and regioselective hydrogen bonding-catalyzed dipolar cycloaddition of activated cis- or trans-alkenes with aryl azides undergo a highly stereospecific photodenitrogenation to form the corresponding cis- or trans- azidirines in high chemical yields. While examples involving disubstituted and trisubstituted triazolines highlight steric challenges encountered in the dipolar cycloaddition reaction, the stereochemical control exerted by the crystalline lattice is enhanced by bulky substituents in the triazoline precursors to generate aziridines photochemically.

CuInSe2 thin film solar cells prepared by low-cost electrodeposition techniques from a non-aqueous bath

Highly crystalline and stoichiometric CIS thin films have been electrodeposited from non-aqueous bath at temperature 130 °C. Superstrate solar cell structure (FTO/CdS/CIS/Au) exhibited 4.5% power conversion efficiency.

Synthesis of CIS Nanoink and Its Absorber Layer without Selenization

Highly crystalline CIS nanoink was synthesized using highly efficient microwave route. Thin films of CIS were fabricated using the developed ink by drop casting method. XRD pattern of CIS thin films indicates that a chalcopyrite phase with good crystallinity can be obtained using developed ink and that the composition of precursor ink can be transferred directly to the thin film without change in the stoichiometry. The developed ink alleviates the need of organic binders/dispersant and high temperature selenization using highly toxic H2Se gas (or Na2Se as a Se source) after deposition of thin film absorber layer. UV-VIS-NIR absorption analysis indicates that CIS thin film has a band gap of around 1.18 eV.

Power rating of photovoltaic modules including validation of procedures to implement IEC 61853‐1 on solar simulators and under natural sunlight

ABSTRACTThis paper describes the measurement of photovoltaic module performance over a range of temperatures and irradiances according to the international standard IEC 61853 Part 1. The purpose of this work is to assess the reproducibility of power matrix measurements obtained using two methods specified in the standard: under natural sunlight with a tracker, and with a solar simulator. A comparison of results using the third principal method (under natural sunlight without tracker) is also summarised for completeness. The same measurement techniques have been employed to measure four modules of different technologies, namely mono and poly crystalline Si, CdTe and CIS. The method used to vary the irradiance in the natural sunlight with tracker and solar simulator approaches is based on un‐calibrated mesh filters. The uniformity and effect on spectrum of the mesh filters have been studied, and the impact of these on the measurements estimated. Measurements from all methods are compared over as much of the ranges as possible. The results show that for all modules, the reproducibility is within the estimated measurement uncertainty. The suitability of the different methods is discussed in light of the results and the limitations of the various methods as applied to different modules technologies. On the basis of the results, parts of IEC 61853 Part 1 will be introduced into the ISO 17025 laboratory accreditation at the European Solar Test Installation (ESTI). Copyright © 2013 John Wiley & Sons, Ltd.

Origin of the Color of π-Conjugated Polymers: Poly(N-n-octyl-3-carbazoyl)acetylene Prepared with a [Rh(norbornadiene)Cl]2 Catalyst

Stereoregular polymerization of (N-n-octyl-3-carbazoyl)acetylene was successfully performed with a [Rh(NBD)Cl]2 (NBD = norbornadiene) catalyst to afford poly(N-n-octyl-3-carbazoyl)acetylene (PNOCzA) as a new type of possible electron-transporting polymer in fairly high yields when triethylamine, chloroform, or dimethylformamide was used as the polymerization solvent. The resulting polymers were composed of amorphous cis−transoid isomers bearing a yellow color or crystalline cis−transoid isomers having an orange color, called a columnar, as a π-conjugated molecular assembly at the solid state. The cis-to-trans isomorization of the yellow and orange polymers was induced by compression at 200 kg/cm2 under vacuum at room temperature for 10 min. The polymers obtained before and after compression were characterized in detail using 1H NMR, wide-angle X-ray diffraction, laser Raman, electron spin resonance, and diffuse reflective UV−vis (DRUV−vis) methods. The data showed that compression of the orange polymers r...

Short‐circuit current of solar cells under artificial light

AbstractA model to estimate the short‐circuit current of a solar cell under artificial light from the short‐circuit current of the same solar cell under AM1.5 1 kW/m2 is described. The results may help designers of solar‐powered portable equipment and consumer products working indoors or under a mixture of artificial and sunlight. It is concluded that the ratio of the short‐circuit currents of the same solar cell generated under fluorescent light of 1 lux illuminance divided by the short‐circuit current generated under standard 1 Sun AM1.5 conditions is around 3 × 10−6 for typical crystalline silicon and CIS solar cells. This value is one order of magnitude greater if the light source considered is an incandescent lamp. In the case of amorphous silicon solar cells the value of the ratio is close to 8 × 10−6 either for fluorescent or incandescent lamps. CdTe solar cells are also considered, and this factor is about 4 × 10−6 under fluorescent light, and four times bigger when an incandescent lamp is used. Some measurements performed validate the figures obtained. Copyright © 2002 John Wiley & Sons, Ltd.

Cis, cis-(3,5-dihydroxycyclohexyl) 3,4-bis(alkoxy)benzoates Thermal behaviour and water absorption

Abstract A homologous series of liquid crystalline cis, cis-(3,5-dihydroxycyclohexyl) 3,4-bis(alkoxy)-benzoates ('two chain' diols) is described. The formation of different mesophase structures by these compounds is influenced by the length of the alkoxy side chains; changes from smectic via cubic to hexagonal columnar mesophases have been established in a certain chain length range. The aggregation to 'supramolecular' structures via hydrogen bonding seems to be necessary for the different mesophases. Not only the behaviour of the freeze dried products, but also that of samples which had absorbed water, either from a saturated atmosphere or from direct contact, is described.

Formation of a trans-cycloadduct from the reaction of difluorocarbene with cis-difluorostilbene

The photochemical isomerization of trans and cis-difluorostilbenes has been studied. In the presence of a photosensitizer (biacetyl, 0.05 mol·−1) about 75% of the trans form can be converted into the crystalline cis form. The reactions of difluorocarbene (CF2) from the Seyferth reagent (PhHgCF3) with cis- and trans-stilbene obey the Skell rule, i. e., stereospecific cycloaddition. However, although the reaction of CF2 with trans-1,2-difluorostilbene yields trans-1,2-diphenyl-perfluorocyclopropane (9) as the only isolable product, the reaction of CF2 with cis-difluorostilbene also gives the same trans-cycloadduct as the only isolable product. A possible mechanistic path involving the homolytic cleavage of the highly activated cyclopropane C—C bond facing the CF2 group is discussed.

1,3‐Dioxanone Derivatives from β‐Hydroxy‐carboxylic Acids and Pivalaldehyde. Versatile Building Blocks for Syntheses of Enantiomerically Pure Compounds. A Chiral Acetoacetic Acid Derivative Preliminary Communication

Abstract(R)‐3‐Hydroxybutyric acid (from the biopolymer PHB) and pivalaldehyde give the crystalline cis ‐ or (R,R)‐2‐(tert‐butyl)‐6‐methyl‐1,3‐dioxan‐4‐one (1a), the enolate of which is stable at low temperature in THF solution and can be alkylated diastereoselectively (→3, 4, 5, and 7). Phenylselenation and subsequent elimination give an enantiomerically pure enol acetal 10 of aceto‐acetic acid. Some reactions of 10 have been carried out, such as Michael addition (→11), alkylation on the CH3 substituent (→13), hydrogenation of the CC bond (→1a) and photochemical cycloaddition (→16). The overall reactions are substitutions on the one stereogenic center of the starting β‐hydroxy acid without racemization and without using a chiral auxiliary.

Concomitant Photochemical and Phase Rearrangements 2. Luminescent and X-Ray Studies on Photochemistry of Cis- and Trans-1,2-Di-(1 -Naphthyl)ethylenes in the Crystalline State

Abstract It is shown that topochemically controlled cis-trans-photoisomerization in crystals of cis-DNE 2-5 μm in size occurs without single crystal destruction. The energy of the newly formed trans-crystal structure is lowered by ca. 5.6 kcal · mole−1. In larger monocrystals the isornerization is accompanied by sample cracking. Photolysis of trans-crystals in the presence of oxygen results in photocyclization and picene formation. The concomitant dimerization and cyclization reactions are not observed in crystalline cis- and trans-DNE which was accounted for by the particular features of the crystal lattice.

Stability of 3-glycosyloxyprolines in an alkaline medium. Synthesis of model compounds

Glycosylation of the hindered secondary alcohol groups in substituted 3- and 4-hydroxyproline by reaction with 3,4,6-tri- O-acetyl- d-glucal and boron trifluoride etherate afforded 40–80% yields of 3- and 4-glycosyloxypyrrolidine-2-carboxylic acids. Modification of the 2,3-unsaturated glycosides of 4-hydroxyproline was achieved by hydrogenation, by addition of acetyl hypobromite, or by epoxidation with hydrogen peroxide in benzonitrile and ring-opening of the resultant 2,3-anhydro derivatives. From these model compounds was selected a 3-glycosyloxyproline that was suitable for assessment of the stability of the glycosyl linkage to base-catalyzed elimination. The model compound was N-acetyl-3- O-(4,6-di- O-acetyl-2,3-dideoxy-α- d- erythro-hexopyranosyl)- cis- d, l-hydroxyproline ethyl ester ( 12). Homogeneity of the compounds was ascertained by high-resolution n.m.r. spectral and chromatographic methods. The glycoside ( 12) of 3-hydroxyproline is stable even in warm base at 50°. The 3- and 4-hydroxyproline glycosides are both more stable to acid hydrolysis than the analogous compounds of serine and threonine. A reliable synthesis of crystalline cis- d, l-3-hydroxyproline ethyl ester hydrochloride is reported that affords quantities of 250 mg or more in overall yield of 15% from inexpensive starting materials.

Laser‐excited raman scattering of crystalline cis–1, 4–polybutadiene

Journal of Polymer Science Part B: Polymer LettersVolume 8, Issue 2 p. 137-142 Article Laser-excited raman scattering of crystalline cis–1, 4–polybutadiene S. W. Cornell, S. W. Cornell Division of Macromolecular Science, Case Western Reserve University, Cleveland, Ohio 44106Search for more papers by this authorJ. L. King, J. L. King Division of Macromolecular Science, Case Western Reserve University, Cleveland, Ohio 44106Search for more papers by this author S. W. Cornell, S. W. Cornell Division of Macromolecular Science, Case Western Reserve University, Cleveland, Ohio 44106Search for more papers by this authorJ. L. King, J. L. King Division of Macromolecular Science, Case Western Reserve University, Cleveland, Ohio 44106Search for more papers by this author First published: February 1970 https://doi.org/10.1002/pol.1970.110080215Citations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume8, Issue2February 1970Pages 137-142 RelatedInformation

Stepwise stereoisomerization of prolycopene, a poly cis carotenoid, to all- trans-lycopene

When solutions of prolycopene, C 48H 56, are illuminated under certain conditions, a subsequent chromatogram shows the presence of 1.3 “intermediate” steric forms, located between the unchanged prolycopene and the all- trans-lycopene zones. The ultraviolet spectral characteristics of these stereoisomers are given. The seven crystalline cis compounds were also characterized in the infrared region. One of the isomers has been identified with the natural product “polycis-lycopene III.” The high number of observed cis forms and their manifold spectral features can only be explained if prolycopene is a poly cis compound which probably contains four cis double bonds. During the stepwise isomerization, prolycopene → all- trans-lycopene, the infrared bands related to the methylated and unmethylated cis double bonds gradually decrease in intensity and disappear when the all- trans stage is reached.