Effect of crystal and powder of CH₃NH₃I on the CH₃NH₃PbI₃ based perovskite sensitized solar cell

Rahul,Singh, Pramod K.,Singh, Rahul,Singh, Vijay,Tomar, S.K.,Bhattacharya, B.,Khan, Zishan H. Elsevier 2017 Materials research bulletin Vol.89 No.-

<P><B>Abstract</B></P> <P>A nanocrystalline sensitizer CH<SUB>3</SUB>NH<SUB>3</SUB>PbI<SUB>3</SUB> is synthesized by reacting methylammonium iodide with lead iodide, and its structural and photovoltaic properties were studied. In this paper we have succeeded in achieving a promising way of synthesizing powder and crystals of CH<SUB>3</SUB>NH<SUB>3</SUB>I. The powder of CH<SUB>3</SUB>NH<SUB>3</SUB>I was synthesized by making a solution of methyl amine and hydroiodic acid (HI) while for getting the crystal of CH<SUB>3</SUB>NH<SUB>3</SUB>I the same procedure was followed with the treatment of ethanol and further CH<SUB>3</SUB>NH<SUB>3</SUB>I powder solution was left in refrigerator (48h). For synthesize perovskite solution of powder and crystal, the equimolar ratio of CH<SUB>3</SUB>NH<SUB>3</SUB>I and PbI<SUB>2</SUB> were mixed in gamma-butyrolactone (GBL) solution. The powder and crystal solution of CH<SUB>3</SUB>NH<SUB>3</SUB>PbI<SUB>3</SUB> were further characterized using various experimental techniques such as x-ray diffraction pattern (XRD), UV⬜visible absorption spectroscopy, scanning electron microscope (SEM), transmission electron microscopy (TEM). A standard perovskite sensitized solar cell (PSSC) has been fabricated using CH<SUB>3</SUB>NH<SUB>3</SUB>PbI<SUB>3</SUB> perovskite and polyethylene oxide (PEO) solid polymer electrolyte.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Clearcut comparative data of perovskite powder vs crystal. </LI> <LI> First clearcut evidence of beneficiality of crystals of pervoskite. </LI> <LI> Science behind PSSC datas are successfully presented. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P> <P>Shows the formation of CH<SUB>3</SUB>NH<SUB>3</SUB>PbI<SUB>3</SUB> (a) synthesised precipitate of methyl ammonium iodide (b) recrystallized perovskite (c) Solution of methyl ammonium tri-lead iodide.</P>

High performing smart electrochromic device based on honeycomb nanostructured h-WO₃ thin films: hydrothermal assisted synthesis

Kondalkar, Vijay V.,Mali, Sawanta S.,Kharade, Rohini R.,Khot, Kishorkumar V.,Patil, Pallavi B.,Mane, Rahul M.,Choudhury, Sipra,Patil, Pramod S.,Hong, Chang K.,Kim, Jin H.,Bhosale, Popatrao N. The Royal Society of Chemistry 2015 Dalton Transactions Vol.44 No.6

<P>Herein, we report honeycomb nanostructured single crystalline hexagonal WO<SUB>3</SUB> (h-WO<SUB>3</SUB>) thin films in order to improve electrochromic performance. In the present investigation, honeycomb nanostructured WO<SUB>3</SUB> with different unit size and nanowire array with highly nanocrystalline frameworks have been synthesized <I>via</I> a hydrothermal technique. The influence of hydrothermal reaction time on the honeycomb unit cells, crystallite size, lithium ion diffusion coefficient and switching time for coloration/bleaching were studied systematically. The electrochromic study reveals that the honeycomb unit cell size has a significant impact on the electrochromic performance. Small unit cells in the honeycomb lead to large optical modulation and fast switching response. A large optical modulation in the visible spectral region (60.74% at <I>λ</I> = 630 nm) at a potential of −1.2 V with fast switching time (4.29 s for coloration and 3.38 s for bleaching) and high coloration efficiency (87.23 cm<SUP>2</SUP> C<SUP>−1</SUP>) is observed in the honeycomb WO<SUB>3</SUB> thin films with a unit cell diameter of 1.7 μm. The variation in color on reduction of WO<SUB>3</SUB> with applied potential has been plotted on an <I>xy</I>-chromaticity diagram and the color space coordinate shows the transition from a colorless to deep blue state.</P> <P>Graphic Abstract</P><P>Honeycomb nanostructured single crystalline hexagonal WO<SUB>3</SUB> (h-WO<SUB>3</SUB>) thin films in order to improve electrochromic performance. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4dt02953d'> </P>

Deep Brain Stimulation: Technology at the Cutting Edge

Rahul S. Shah,Su-Youne Chang,민훈기,조장희,Charles D. Blaha,Kendall H. Lee 대한신경과학회 2010 Journal of Clinical Neurology Vol.6 No.4

Deep brain stimulation (DBS) surgery has been performed in over 75,000 people worldwide, and has been shown to be an effective treatment for Parkinson’s disease, tremor, dystonia, epilepsy,depression, Tourette’s syndrome, and obsessive compulsive disorder. We review current and emerging evidence for the role of DBS in the management of a range of neurological and psychiatric conditions, and discuss the technical and practical aspects of performing DBS surgery. In the future, evolution of DBS technology may depend on several key areas, including better scientific understanding of its underlying mechanism of action, advances in high-spatial resolution imaging and development of novel electrophysiological and neurotransmitter microsensor systems. Such developments could form the basis of an intelligent closed-loop DBS system with feedback-guided neuromodulation to optimize both electrode placement and therapeutic efficacy.

Inkjet Printing of Yttria Stabilized Zirconia Nano Particles on Metal Substrates

S. H. Rahul,K. Balasubramanian,Sriram Venkatesh 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

This paper describes a novel methodology of coating Yttria stabilized Zirconia (YSZ) suspensions on AISI316L steel substrates and involves a micro structural investigation to understand the sintering behavior. Nano sized particles are used at lowering of sintering temperature. Nano particle suspension inks prepared through high energy milling process is visibly stable due to ionic charge carriers in binder and solvent. Deposition of suspended material was done through inkjet printing (IJP) and spin coating (SC) processes. Print head offset in X and Y directions lead to fabrication of homogeneous layers. Inkjet printing at elevated temperatures is useful especially in controlling nano particle seepage through porous substrates. Low temperature sintering of suspended particles in the ink leads to development of porous YSZ films due to the presence of carrier solvent and binder/dispersants in the ink. Sintered films exhibit completely stable tetragonal zirconia with uniformly porous microstructure. Pore sizes of 50 nm and 100 nm have been reported at least for inkjet printed and spin coated films respectively. The homogeneity observed in pores of YSZ film is a typical characteristic of inkjet printing process which is attributed to the layer by layer stacking of nano particles during the deposition process.

High TCR and MR of La<SUB>0.7</SUB>Ca<SUB>0.2</SUB>Ba<SUB>0.1</SUB>MnO₃Agx Composite Near Room Temperature

Rahul Tripathi,Anjana Dogra,G. L. Bhalla,V.P.S. Awana,H. Kishan 한국자기학회 2008 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Electrical and structural properties of ionic liquid doped polymer gel electrolyte for dual energy storage devices

Singh, Rahul,Bhattacharya, B.,Gupta, Meenal,Rahul, Meenal,Khan, Zishan H.,Tomar, S.K.,Singh, Vijay,Singh, Pramod K. Pergamon Press 2017 International journal of hydrogen energy Vol.42 No.21

<P><B>Abstract</B></P> <P>This paper reports the synthesis, characterization and dual electrochemical application of a new kind of ionic liquid (IL) based polymer electrolyte. The ionic liquid 1, 2-dimethyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide (DMPImTFSI) and polymer Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) have been chosen for present study. The electrical conductivity measurement shows many fold enhancement of ionic conductivity by blending IL into polymer matrix. Scanning electron microscopy (SEM) image confirms the uniform surface morphology of the synthesized thin film and cross-section image shows the interface layer of polymer and electrode. We have fabricated an efficient dye sensitized solar cell (DSSC) and electric double layer capacitor (EDLC) using IL-polymer electrolyte (optimized maximum conductivity) system which further affirms that this material is highly stable and reliable for long duration in energy devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel polymer gel electrolyte system for dual energy storage electrochemical application. </LI> <LI> Liquid like ionic conductivity of gel polymer electrolyte with high transparency in the film. </LI> <LI> Highly stable electrical performance of DSSC and EDLC devices. </LI> </UL> </P>

Effect of Pr Doping in La-Sn-Mn-O

Neeraj Kumar,Rahul Tripathi,Anjana Dogra,V.P.S. Awana,H. Kishan 한국자기학회 2008 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Highly Efficient Visible Light Mediated Azo Dye Degradation Through Barium Titanate Decorated Reduced Graphene Oxide Sheets

Monisha Rastogi,H.S. Kushwaha,Rahul Vaish 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.2

This study investigates BaTiO3 decorated reduced graphene oxide sheetsas a potential visible light active catalyst for dye degradation (RhodamineB). The composites were prepared through conventional hydrothermalsynthesis technique using hydrazine as a reducing agent. A number oftechniques have been employed to affirm the morphology, compositionand photocatalytic properties of the composites; these include UV-visiblespectrophotoscopy that assisted in quantifying the concentration differenceof Rhodamine B. The phase homogeneity of the composites was examinedthrough x-ray powder diffraction (XRD) and high resolution transmissionelectron microscopy (HRTEM) was employed to confirm the orientationof the BaTiO3 particles over the reduced graphene oxide sheets. Photoluminescence (PL) emission spectra assisted in determining thesurface structure and excited state of the catalyst. Fourier transformedinfrared(FTIR) spectra investigated the vibrations and adsorption peak of the composites, thereby ascertaining the formation ofreduced graphene oxide. In addition, diffuse reflectance spectroscopy (DRS) demonstrated an enhanced absorption in the visibleregion. The experimental investigations revealed that graphene oxide acted as charge collector and simultaneously facilitatedsurface adsorption and photo-sensitization. It could be deduced that BaTiO3-reduced graphene oxide composites are ofsignificant interest the field of water purification through solar photocatalysis.

Photoelectrocatalysis of Cefotaxime Using Nanostructured TiO₂ Photoanode: Identification of the Degradation Products and Determination of the Toxicity Level

Kondalkar, Vijay V.,Mali, Sawanta S.,Mane, Rahul M.,Dandge, P. B.,Choudhury, Sipra,Hong, Chang K.,Patil, Pramod S.,Patil, Shivajirao R.,Kim, Jin H.,Bhosale, Popatrao N. American Chemical Society 2014 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.53 No.47

<P>Nanostructured TiO<SUB>2</SUB> thin films were fabricated via a facile, economical, and energy-efficient microwave-assisted dip-coating (MWDC) technique. Further, the resulting TiO<SUB>2</SUB> films were characterized by means of X-ray diffraction, high-resolution transmission electron microscopy, selected-area electron diffraction, Fourier transform Raman spectroscopy, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy techniques for their phase structure, morphology, and optical and surface properties. TiO<SUB>2</SUB>-mediated photoelectrocatalytic degradation of the antibiotic cefotaxime (CFX) in an aqueous solution was studied by varying the pH under UV illumination. The degradation intermediates and possible reaction degradation path of CFX were analyzed by electrospray ionization time-of-flight mass spectrometry (MS). The MS spectra revealed that degradation of CFX occurs through β-lactum corresponding to the cleavage of the cephem nucleus. Moreover, the antibacterial activity of CFX prior to and after photoelectrocatalytic degradation was carried out to analyze the toxicity against <I>Staphylococcus aureus</I> and salmonella typhi bacteria. Interestingly, it was observed that the antibiotic activity was drastically inhibited after photoelectrocatalytic degradation of the CFX solution. The photoelectrocatalytic stability of a nanostructured TiO<SUB>2</SUB> electrode was evaluated by recycling the degradation experiments. It was observed that there was no significant decrease in the catalytic activity, indicating potential applications of the TiO<SUB>2</SUB> electrode prepared by the MWDC method.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/iecred/2014/iecred.2014.53.issue-47/ie501821a/production/images/medium/ie-2014-01821a_0014.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ie501821a'>ACS Electronic Supporting Info</A></P>

Development of nanocoral-like Cd(SSe) thin films using an arrested precipitation technique and their application

Khot, Kishorkumar V.,Mali, Sawanta S.,Pawar, Nita B.,Kharade, Rohini R.,Mane, Rahul M.,Kondalkar, Vijay V.,Patil, Pallavi B.,Patil, Pramod S.,Hong, Chang K.,Kim, Jin H.,Heo, Jaeyeong,Bhosale, Popatrao The Royal Society of Chemistry 2014 New journal of chemistry Vol.38 No.12

<P>Nanocrystalline cadmium sulfoselenide thin films have been synthesized using a self-organized arrested precipitation technique with different deposition times using triethanolamine as a complexing agent. Optical, structural, morphological and photoelectrochemical solar cell properties were investigated as a function of deposition time. A UV-Vis-NIR absorption study suggested a direct allowed transition type and the band gap energy decreased from 2.01 to 1.86 eV with the increase in deposition time. X-ray diffraction studies revealed that the thin films are nanocrystalline by nature with a pure hexagonal crystal structure and a calculated crystallite size of 51–68 nm. Field emission scanning electron microscopy demonstrated that the surface morphology was altered from nanoflakes to assorted nanoflakes–nanospheres and finally to a nanocoral-like morphology. X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy showed that the composition of the Cd(SSe) thin films was of good stoichiometry. Electrical conductivity and thermoelectric power measurements confirmed that the deposited films were n-type semiconductors. From <I>J–V</I> measurements, a highest photo-conversion efficiency of 0.57% was achieved. The significant boost in the PEC performance might be due to the improved crystallinity along with lower values of the grain boundary resistance, dislocation density and the microstrain of the Cd(SSe) thin films.</P> <P>Graphic Abstract</P><P>First-time synthesis of nanoflakes to nanocoral-like Cd(SSe) thin films using a novel arrested precipitation technique with triethanolamine as complexing agent (<I>η</I> = 0.57%). <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4nj01319k'> </P>