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In recent years, it has been established that solar cells based on organic-inorganic hybrid perovskite materials have substantial potential for the development of highly efficient photovoltaic devices and offers robust opportunities for research to the scientific community and industry. Power conversion efficiency (PCE) of perovskite solar cells (PSCs) have already surpassed 24.8 % within a decade, which is now third highest efficiency among single-junction photovoltaic materials. This report briefly introduces hybrid-halide perovskite materials, their structural properties, various possible device architectures and a comparative study of photo-voltaic performance. For commercialization, high stability of devices is must and here we have thoroughly discussed possible degradation mechanisms of PSCs, that is, moisture; oxygen; heat; structural stability; UV-light effect; defect-states, ion-migration and various approaches to passivity based upon recent reports. A proper encapsulation with optimized chemical composition (enhanced interaction between organic/inorganic cation and BX6 octahedron) PSCs could possess superior stability for long-run while maintaining optoelectronic properties. [ABSTRACT FROM AUTHOR]

We report the fabrication of low cost highly structured silver (Ag) capped aluminium (Al) nanorods (NRs) as surface enhanced Raman spectroscopy (SERS) substrate utilising the glancing angle deposition technique. The nano-capping of silver onto the Al NRs can concentrate the local electric field within the minimal volume that can serve as hotspots. The average size of the Ag nanocaps was 50 nm. The newly proposed nanoporous Ag capped Al NRs as SERS substrate could detect the Raman signal of rhodamine 6G (R6G) up to 10−15 molar concentration. The significant enhancement in the Raman signal of 107 was achieved for Ag capped Al NRs considering R6G as a probe molecule. Using the developed SERS substrate, we recorded Raman spectra for Escherichia coli bacteria with its concentration varying from 108 colony forming units per ml (CFU ml−1) up to 102 CFU ml−1. All the reported Raman spectra were acquired by a portable handheld Raman spectrometer. Hence, this newly proposed low cost, effective SERS substrate can be used commercially for the onsite detection of clinical pathogens. The 3D finite difference time domain simulation model was performed for Ag capped Al nanostructure to understand the generation of hotspots. The simulated results show excellent agreement with the experimental results. We fabricated uncapped Ag nanorods of similar dimensions and performed the experimental measurements and simulations for comparison. We found a significant enhancement in Ag capped Al NRs compared to the long Ag NRs. The description of the Raman signal enhancement has been elaborated. [ABSTRACT FROM AUTHOR]

We report the effect of humidity on the electrical properties of different conductivity grades (low and high) of the polymer poly (3, 4‐ethylenedioxythiophene)‐poly (styrenesulfonate) (PEDOT : PSS) and their nanocomposites comprising of single walled carbon nanotubes (SWCNT). Polymer nanocomposites were prepared by using PEDOT : PSS with different weight ratio of chemically treated single walled carbon nanotubes (CT‐SWCNT). Humidity dependent change in resistance of thin films of pure and nanocomposites was measured and analyzed in detail. This basic study on the various conductivity grade PEDOT : PSS polymers and their SWCNT nanocomposites elucidate their response to humidity. It was found that the resistance of low and high conductivity grade pristine PEDOT : PSS films show opposite trends with respect to humidity. Interestingly these trends reverse in their nanocomposites containing CT‐SWCNT. The present study might find useful information for researchers working in the area of polymer nanocomposite based devices and applications. [ABSTRACT FROM AUTHOR]

The quest for cost effective and efficient solid-state electrolytes is a primary goal for dye sensitized solar cells (DSSCs). The present study describes an experimental approach of synthesizing simple composite electrolytes from iodide-triiodide ions (I−/I3−) incorporated into a polyaniline/thiourea matrix for solid-state DSSC applications. This electrolyte composition can be effectively used to decrease the probability of recombination at the TiO2/electrolyte interface and increase the catalytic process of I3− reduction at the electrolyte/counter electrode interface. The application of the optimized electrolyte in DSSC results in increased open-circuit voltage as well as short circuit current density, thereby increasing the overall efficiency by 73% as compared to the reference electrolyte. The present composition can prove to be a promising redox medium for solid state DSSCs. [ABSTRACT FROM AUTHOR]

ABSTRACT The nanocomposite of titanium-di-oxide (TiO2)/iodine (I2) in polyvinyl alcohol (PVA) matrix has been explored to be used in hydrogen peroxide (H2O2) sensing applications for the first time. The proposed nanocomposite can be easily casted in the form of thin film on glass substrates as well as free standing membranes. These nanocomposite films and membranes exhibit reduced resistance values and easily observable colour changes in the presence of H2O2. The films also exhibit significant quenching in photoluminescence emission properties upon H2O2 exposure. These sensor responses have been attributed to redox reactions at nanocomposite films and H2O2 interface. This study indicates an easy to fabricate, flexible and environmental friendly sensing platform for H2O2. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42257. [ABSTRACT FROM AUTHOR]

Women as a group have long been treated unequal to men, and subjugated and exploited just because they are women. Till now, women have been the most marginalized and vulnerable group across the societies and economic systems. However, because of the sustained and dedicated works of Feminism, now their right to equality has been recognized and legalized in almost all the countries. Over the past 100 years, since Feminism began as a moment and theory, now we have a large body of knowledge and a vast experience to understand and redress women's inequality and injustice significantly. The present paper is an attempt to represent the picture of women from a gender perspective. Gender analysis shows that 'Women are not born weak, they are made weak'. I myself fully subscribe to this view. Although the biological differences between men and women cannot be denied, but despite this women are as efficient as men. They are not born by nature inferior to men in reason, intellect, talent or in any other respect. In fact, they are made weak by religious, cultural, socio-economic and other conditions prevailing in the patriarchal society. Sexual and biological difference is a genuine difference but should not be a ground to distribute burden and benefit. The concept of women equality assumes that women are different from men, but treated as weaker and need privileges to be at par with men. This paper also tries to explore the factors responsible for the inferior and secondary status of women in society and suggests some serious strategies to enhance the status of women and to make them enable to live a dignified life. [ABSTRACT FROM AUTHOR]

Abstract: We report the studies on photoluminescence (PL) and electroluminescence (EL) spectra of organic light emitting diodes (OLED) based on most widely used light emitting material, i.e., Tris-(8-hydroxyquinoline) aluminum (Alq3). PL studies from the edges and top surface were carried out on different thicknesses of single layer of Alq3 coated on glass substrate and the PL intensity from the edges was found to be more than that from the top surface. On the other hand EL emission intensity from the surface was found to be larger than that from the edges of the OLED device. The discrepancy in the PL and EL emission from edge and the top surfaces is discussed. The effect of the thickness of Alq3 layer on the PL intensity and the emission spectra are also investigated. [Copyright &y& Elsevier]

We report the measurement of spatial coherence properties of light emitted by organic electroluminescent devices based on tris-(8-hydroxyquinoline) aluminum. Coherence measurements were performed using Young’s double slit experiment. Fourier-transform technique was used for the measurement of visibility of the interference fringes from which the modulus of the degree of spatial coherence was determined. Experimental results were compared with the theoretical values and it is shown that the coherence properties of the light emitted by a simple organic light emitting device match with those of practical Lambertian sources. [ABSTRACT FROM AUTHOR]

Investigates the shock-induced polarization in normal-hexane. Separation of copper electrodes by a polycarbonate ring; Details on the thickness and diameter of the front and back electrodes; Use of tilt pin method to establish the reference time and projectile tilt of the electrodes.

The energy transfer mechanism has been studied in 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyram (DCM) doped zinc complex bis[2-(2-hydroxyphenyl) bezoxazolate]zinc [Zn(hpb)2]. The photoluminescence of the zinc complex and the optical absorption of the dye molecule have been found to have a large overlap favoring Förster mechanism for energy transfer from the host to the dye molecule. The photoluminescence of the host–guest system has been assigned to Förster type energy transfer where as the electroluminescence has been found to be dominated by trap assisted recombination and subsequent decay of excitons. The charge carrier trapping has been supported by electrical transport studies. [ABSTRACT FROM AUTHOR]

A correction to the article “Spatial coherence properties of electroluminescence from Alq3-based organic light emitting diodes” that was published in the May 9, 2007 issue is presented.

A new perovskite material based on ethylene-diamine-dichloride and lead iodide as organic and inorganic precursors respectively was synthesized. Thin films of perovskite material were characterized using SEM, UV-Visible spectroscopy, XRD, and FT-IR. Sensing properties of inorganic organic perovskite thin films were studied and it was found to be selective for ammonia detection. Ammonia being one of the most hazardous and volatile chemical becomes necessary to detect. Color change of perovskite film from yellow to orange was observed in the presence of ammonia vapors. Electrical measurements showed decrease in resistance in the presence of ammonia vapors. Low concentration upto 50 ppm can be easily detected in approximately 40 s. The present method for detecting ammonia is unique, simple, selective, low cost and can be easily implemented for the field studies. [ABSTRACT FROM AUTHOR]

We report enhanced color purity of hybrid organic-inorganic light emitting diode based on polyfluorene-CdSe/ZnS quanum dot (QD) blend as emissive layer. Effect on structural, optical and electrical properties of different doping concentration (0–100 wt.%) of QD in polyfluorene (PFO) was studied. Photoluminescence and electroluminescence spectra confirm the β-formation of PFO by incorporation of CdSe/ZnS QD. Photoluminescence (PL) of blend film was also compared with another method based on one dimensional photonic band gap (1D-PBG) structure that has been used for color purity. In both the cases, that is, QD doped device and 1D-PBG based structures the narrowing of PL spectra was observed. But the fabrication of QD-doped device for color purity is easier than fabricating 1D-PBG structure using multilayer dielectric coating. The present study might find application for QD based color displays, where color purity is an important requirement. [ABSTRACT FROM AUTHOR]

Programmable nanoscale carriers, such as liposomes and DNA, are readily being explored for personalized medicine or disease prediction and diagnostics. The characterization of these nanocarriers is limited and challenging due to their complex chemical composition. Here, we demonstrate the utilization of surface-enhanced Raman spectroscopy (SERS), which provides a unique molecular fingerprint of the analytes while reducing the detection limit. In this paper, we utilize a silver coated nano-bowl shaped polydimethylsiloxane (PDMS) SERS substrate. The utilization of nano-bowl surface topology enabled the passive trapping of particles by reducing mobility, which results in reproducible SERS signal enhancement. The biological nanoparticles' dwell time in the nano-trap was in the order of minutes, thus allowing SERS spectra to remain in their natural aqueous medium without the need for drying. First, the geometry of the nano-traps was designed considering nanosized bioparticles of 50-150 nm diameter. Further, the systematic investigation of maximum SERS activity was performed using rhodamine 6 G as a probe molecule. The potential of the optimized SERS nano-bowl is shown through distinct spectral features following surface- (polyethylene glycol) and bilayer- (cholesterol) modification of empty liposomes of around 140 nm diameter. Apart from liposomes, the characterization of the highly crosslinked DNA specimens of only 60 nm in diameter was performed. The modification of DNA gel by liposome coating exhibited unique signatures for nitrogenous bases, sugar, and phosphate groups. Further, the unique sensitivity of the proposed SERS substrate displayed distinct spectral signatures for DNA micelles and drug-loaded DNA micelles, carrying valuable information to monitor drug release. In conclusion, the findings of the spectral signatures of a wide range of molecular complexes and chemical morphology of intra-membranes in their natural state highlight the possibilities of using SERS as a sensitive and instantaneous characterization alternative., Competing Interests: The authors declare no conflicts of interest., (© 2024 Optica Publishing Group.)