Chemically synthesized Bi2S3, CuS and Bi2S3/CuS heterostructure materials as counter electrode: Dye sensitized solar cell application

143-149In the present work, we have successfully synthesized Bi2S3, CuS, and its heterojunction Bi2S3/CuS thin film on fluorine doped tin oxide (FTO) coated glass as counter electrodes. These depositions are done by simple, cost effective, and simply executable sequential chemical bath deposition (S-CBD) method. Well optimized preparative parameters led to the formation of good quality thin films of Bi2S3 and CuS films and heterojunction. The structural validation Bi2S3, CuS, and its heterojunction were achieved by X-ray diffraction and Raman scattering, surface morphological study observed through Scanning Electron Microscopy (SEM) and topology was confirmed by Atomic Force Microscopy (AFM). We have employed Bi2S3/CuS heterostructure as a counter electrode (CE) in dye-sensitized solar cell (DSSC). We have observed different parameters like short circuit current density (Jsc), open circuit voltage (Voc), Fill Factor (FF) and efficiency (n) by Current–voltage (J-V) characteristics. Though we do not achieve an anticipated outcome for heterostructure compared with conventional Platinum and Carbon black counter electrode, CuS separately found worthy as Counter electrode (CE) in DSSC

ZnO/CuSCN nano-heterostructure as a highly efficient field emitter: a combined experimental and theoretical investigation

We report the synthesis of two-dimensional porous ZnO nanosheets, CuSCN nanocoins, and ZnO/CuSCN nano-heterostructure thin films grown on fluorine-doped tin oxide substrates via two simple and low-cost solution chemical routes, i.e., chemical bath deposition and successive ionic layer adsorption and reaction methods. Detail characterizations regarding the structural, optoelectronic, and morphological properties have been carried out, which reveal high-quality and crystalline synthesized materials. Field emission (FE) investigations performed at room temperature with a base pressure of 1 × 10–8 mbar demonstrate superior FE performance of the ZnO/CuSCN nano-heterostructure compared to the isolated porous ZnO nanosheets and CuSCN nanocoins. For instance, the turn-on field required to draw a current density of 10 μA/cm2 is found to be 2.2, 1.1, and 0.7 V/μm for the ZnO, CuSCN, and ZnO/CuSCN nano-heterostructure, respectively. The observed significant improvement in the FE characteristics (ultralow turn-on field of 0.7 V/μm for an emission current density of 10 μA/cm2 and the achieved high current density of 2.2 mA/cm2 at a relatively low applied electric field of 1.8 V/μm) for the ZnO/CuSCN nano-heterostructure is superior to the isolated porous ZnO nanosheets, CuSCN nanocoins, and other reported semiconducting nano-heterostructures. Complementary first-principles density functional theory calculations predict a lower work function for the ZnO/CuSCN nano-heterostructure (4.58 eV), compared to the isolated ZnO (5.24 eV) and CuSCN (4.91 eV), validating the superior FE characteristics of the ZnO/CuSCN nano-heterostructure. The ZnO/CuSCN nanocomposite could provide a promising class of FE cathodes, flat panel displays, microwave tubes, and electron sources

Influence of surface passivation by MgO on photovoltaic performance of SnO2 based dye-sensitized solar cells

The study highlights effect of surface modification of SnO2 photoelectrode by MgO coating on photovoltaic properties of dye-sensitized solar cells (DSSCs). A thin coating of MgO on SnO2 photoelectrode was prepared using sol-gel-derived dip coating technique. The bare SnO2 and MgO coated SnO2 composite photoanodes was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and UV–vis spectrophotometer. The optical absorption study revealed that the modification in SnO2 by MgO coating caused an increase in absorption by photoanode in visible region. The solar cell was demonstrated by preparing FTO|SnO2|Dye|MgO|Electrolyte|Pt coated FTO device structure and tested with current density-voltage (J-V) measurement. The effect of precursor concentration of MgO coating on the performance of DSSCs were investigated. It was found that, optimized coating of MgO for 90 seconds on SnO2 improved all photovoltaic parameters, resulting in enhancement in efficiency by 42% compared to that of DSSC with bare SnO2 photoanode. The coating of MgO would have reduced the trap states and suppressed interfacial recombination losses by preventing back electron transfer from the conduction band of the semiconductor to HOMO of dye molecule or redox species

"Basic idea, advance approach": Efficiency boost by sensitization of blended dye on chemically deposited ZnO films

The state of art is shown to develop attractive, low cost, colorful, and device grade dye sensitized solar cells using chemically synthesized ZnO. Metal free organic dyes showing unlike absorption coverage in the visible part of solar spectrum has been used to produce colorful solar cells. By mimicking the basic idea of blending two individual colors of the dyes namely, Coumarin 343 (yellow) and Eosin-Y (red) to get orange color which has been utilized toward advanced colorful approach in order to boost the device performance. Correlation is made between the optical absorption spectra of individual and blended dyes with incident photon to current conversion efficiency (IPCE). The solar cell performance under illumination (100 mW/cm, AM 1.5G) of individual and blended dyes on ZnO films have been investigated. The obtained efficiency ranges from 0.02 to 1.98% for individual dyes whereas the efficiency boosts up to 2.45% has been observed for blended dye.PKB is thankful to DST-SERB in support of financial assistance through the Fast Track Young Scientist Project (SR/FTP/PS-063/2012, dated 06/11/2013). BRS is thankful to DST Project (SR/S2/CMP-0026/2010 and SB/S2/CMP-32/2013) And Director, VNIT for financial support under ULR grant.Peer Reviewe

Fabrication of titanium dioxide (TiO2) and mercury sulfide (HgS) heterojunction for photoelectrochemical study

Abstract This work reports a chemical solution sensitization of HgS nanocrystals on mesoporous TiO2 films for different deposition times. The adsorption of the precursor ions and the surface growth of the crystal were found to be affected during the temporal deposition of the HgS over spin-coated TiO2 films. The synthesized electrodes were characterized by structural, morphological, wettability, optical, photovoltaic, and electrochemical performances. The results designate the qualitative confirmation of the TiO2/HgS heterojunction formation, and the combination is explored for the photovoltaic application, which is first of its kind

Correction to: Fabrication of titanium dioxide (TiO2) and mercury sulfide (HgS) heterojunction for photoelectrochemical study

In the original version of this article, the name of the following author name was not correct