Application of porosities in the transparent electrode layer of a perovskite solar cell for performance enhancement.

Substitution of monocrystalline or polycrystalline silicon as active materials in photovoltaics with highly efficient perovskite materials is quite common. Although perovskite materials offer better flexibility, are cost-effective, and have higher conversion efficiency, they still require structural modifications for better performance. This study quantitatively investigates how mesoporous top surfaces improve the performance of methylammonium lead iodide (C H 3 N H 3 P b I 3) perovskite solar cells. In fact, both the diameter and the depth of the pores have been tuned to achieve better performance. The performance is further optimized by replacing mesoporous active material with planar active material coated with mesoporous indium tin oxide (ITO). We have demonstrated that the proposed structure achieves the maximum conversion efficiency (η) of 27.43% with an open-circuit voltage (V O C ) of 1.07 V and a short circuit current density (J S C ) of 29.09m A/c m 2, with a fill factor (FF) of 88.10%.

Effect of modified double-sided grating structures on efficiency enhancement of thin-film silicon solar cells.

Enhancement of optical to electrical conversion is vital for improving the efficiency of any solar cell. In recent years, use of thin films instead of bulk wafers has resulted in a huge reduction of production cost, and as such, efficiency enhancement of thin-film solar cells is considered in this study. Though this enhancement depends on several factors, most significant among them is the increase in light absorption within the active material of the solar cell. In this work, various types of grating structures on both sides of active solar cell material for light trapping are studied in detail, and a new type of arrangement of optimized grating structure that significantly improves the light absorption is selected. Enhancement of light absorption for change in dielectric material of the grating structure without changing the active material is also observed. Along with structural optimization, simulated electrical characterization of the samples was also performed, which yields a short-circuit current density of 29.27mA/cm2 with conversion efficiency of 14.51%, having a fill factor of 0.83 for a typical ultrathin layer of active material of thickness 2 µm. This is quite significant because typical cells of this category have much lesser conversion efficiency.

Synthesis, characterization and cytocompatibility assessment of hydroxyapatite-polypyrrole composite coating synthesized through pulsed reverse electrochemical deposition.

Composite coating of hydroxyapatite-polypyrrole is synthesized with the help of pulsed reverse electrochemical deposition method from aqueous bath through in-situ formation and co-deposition of both phases simultaneously over metallic stainless steel surface. The inter phase bonding along with surface energy variation and morphology is tuned with the help of deposition current density, deposition time and reverse duty cycle. Hydroxyapatite (HA) lattice exhibits unidirectional growth along the highest atomic plane of 〈111〉 parallel to the coating surface. Different kind of deposited hydroxyapatite structures, namely lamellar and spherical particle scaffold, are observed at moderate and high current densities respectively together with the incorporation of polypyrrole (PPy) phase in between. Pyrrole ring stretching and bond strengthening represent the bonding with hydroxyapatite lattice, which in turn helps to increase the overall corrosion resistance of composite coating by ten-fold as compared to bare PPY coating. The coating deposited with moderate current density (10 mA/cm2) seems to be the optimum one regarding the faster-interconnected growth of MG63 cells over the coating surface along with highest corrosion resistance and anodic passivation capability. Presence of sub-micron level ceramic hydroxyapatite scaffold along with polymer filler material makes this composite biocompatible coating as a potential candidate to use over the load bearing metallic implant surfaces due to its sufficient elasticity along with superior toughness.

Single Injection Technique Prolotherapy for Hypermobility Disorders of TMJ Using 25 % Dextrose: A Clinical Study.

INTRODUCTION: Hypermobility disorders of the Temporomandibular joint (TMJ) can be treated by both conservative and surgical approaches. Conservative approaches should be considered as first line treatment for such disorders. Prolotherapy with 25 % dextrose being injected into the posterior pericapsular tissues is one such treatment modality with favorable outcomes. AIM: To study the efficacy of single injection of 25 % dextrose in pericapsular tissues in the management of hypermobility joint disorders of TMJ as first line treatment. PATIENTS AND METHODS: We have studied a total of 23 patients suffering from either chronic recurrent dislocation or subluxation of the TMJ who were treated with the single injection technique prolotherapy with 25 % dextrose into the pericapsular tissues along with auriculotemporal nerve block and found encouraging results. RESULTS: Overall success rate in our study was 91.3 % (21/23) with a minimum follow up period of 13.9 months. Number of successfully treated patients requiring one injection was 7 (30.4 %), two injections was 8 (34.7 %) and requiring three injections was 6 (26.1 %). There were no permanent complications. CONCLUSION: Hence the use of 25 % dextrose as a proliferant to treat hypermobilty disorders of the TMJ is recommended by us as a first line treatment option as it is safe, economical and an easy procedure associated with minimal morbidity.

Synthesis of calcium hydrogen phosphate and hydroxyapatite coating on SS316 substrate through pulsed electrodeposition.

The orthopaedic implants for human body are generally made of different biomaterials like stainless steels or Ti based alloys. However, it has been found that from surface properties point of view, none of these materials is attractive for fast tissue or cell growth on the surface of implant. This is one of the most important criteria to assure quick bonding between implant and body tissues vis-à-vis minimum recovery time for the patient. Keeping in view of the above facts, this work involves the pulsed electro-deposition coating of biocompatible hydroxyapatite and its group compounds from a diluted bath of calcium and phosphate salt at various current densities over the biomaterial sheet of SS316. SEM study confirms different morphologies of the coatings at different current densities. Characterization techniques like X-ray diffraction, SEM with EDX and FTIR have been used to confirm the phase and percentage quantity of hydroxyapatite compound in the depositions. This coating can serve as a medium for faster tissue growth over the metallic implants.

Semianalytical approach to study the loss characteristics of a symmetrical multilayered plasmonic waveguide.

A metal waveguide of finite width and thickness surrounded by a dielectric provides increased propagation length of the surface plasmon polariton and is therefore called long-range surface plasmon polaritons (LR-SPP). In this work, a new structure is proposed by modifying the refractive index of the dielectric surrounding the metal waveguide, leading to further improvement of the propagation length. It is shown that, when the single dielectric surrounding is replaced by a multilayered surrounding where each layer has different thicknesses and refractive index, the propagation loss gets reduced, leading to increased propagation length of the LR-SPP. The propagation loss is calculated semianalytically from the FWHM of the Lorentzian peak obtained in the plot of excitation efficiency of such waveguide for different values of the propagation constant. Before doing this calculation, the 2D variation of refractive index is first converted into a 1D effective refractive index. All the steps of analysis are discussed in detail, and, wherever necessary, the calculated results are matched with similar results of other researchers.