Comparative study between pure and manganese doped copper sulphide (CuS) nanoparticles

The pure CuS and Mn2+ doped CuS nanoparticles are synthesized by wet chemical route. The CuS phase and hexagonal crystal structure is confirmed by the powder X-ray diffraction and Raman analysis. The vibrational bonds present in the respective synthesized samples are confirmed by Fourier transformed infra-red spectroscopy. The spherical shapes of the nanoparticles are validated by the electron diffraction in scanning and transmission mode. The thermal analysis showed the Mn2+ doped CuS nanoparticles to be more stable than pure CuS nanoparticles. The thermal parameters determined using Coats-Redfern relation stated thermal activation energy and enthalpy change values are highest in the higher temperature range. The Seebeck coefficient variation with temperature and ambient condition Hall effect measurements showed the synthesized nanoparticles to be semiconducting and p-type in nature. The magnetic properties study by Gouy method showed the nanoparticles to be paramagnetic.

Improved light-harvesting and suppressed charge recombination by introduction of a nanograss-like SnO2 interlayer for efficient CdS quantum dot sensitized solar cells

Quantum dot sensitized solar cell (QDSSC) performance is primarily limited by the recombination of charges at the interfaces of TiO2/quantum dot (QD) sensitizer/electrolyte. Hence, blocking or suppressing the charge recombination is an essential requirement to elevate the QDSSC performance to the next level. To retard the charge recombination, herein, we propose the introduction of a SnO2 nanograss (NG) interlayer on the surface of TiO2 using the facile chemical bath deposition method. The SnO2 NG interlayer not only inhibits the interfacial recombination processes in QDSSCs but also enhances the light-harvesting capability in generating more excitons. Hence, the TiO2/SnO2 NG/CdS QDSSCs can achieve the power conversion efficiency of 3.15%, which is superior to that of a TiO2/CdS device (2.16%). Electrochemical impedance spectroscopy, open-circuit voltage decay and dark current analyses confirm that the recombination of charges at the photoanode/electrolyte interface is suppressed and the life time is improved by introducing the SnO2 NG interlayer between the TiO2 and CdS QD sensitizer.

Compound Copper Chalcogenide Nanocrystals

This review captures the synthesis, assembly, properties, and applications of copper chalcogenide NCs, which have achieved significant research interest in the last decade due to their compositional and structural versatility. The outstanding functional properties of these materials stems from the relationship between their band structure and defect concentration, including charge carrier concentration and electronic conductivity character, which consequently affects their optoelectronic, optical, and plasmonic properties. This, combined with several metastable crystal phases and stoichiometries and the low energy of formation of defects, makes the reproducible synthesis of these materials, with tunable parameters, remarkable. Further to this, the review captures the progress of the hierarchical assembly of these NCs, which bridges the link between their discrete and collective properties. Their ubiquitous application set has cross-cut energy conversion (photovoltaics, photocatalysis, thermoelectrics), energy storage (lithium-ion batteries, hydrogen generation), emissive materials (plasmonics, LEDs, biolabelling), sensors (electrochemical, biochemical), biomedical devices (magnetic resonance imaging, X-ray computer tomography), and medical therapies (photochemothermal therapies, immunotherapy, radiotherapy, and drug delivery). The confluence of advances in the synthesis, assembly, and application of these NCs in the past decade has the potential to significantly impact society, both economically and environmentally.

Recombination control in high-performance quantum dot-sensitized solar cells with a novel TiO2/ZnS/CdS/ZnS heterostructure

A superior photovoltaic performance is obtained with a TiO₂/ZnS/CdS/ZnS heterostructure with controlled recombination.

Controlled growth of a nanoplatelet-structured copper sulfide thin film as a highly efficient counter electrode for quantum dot-sensitized solar cells

0.6 M acetic acid in CuS CE preparation shows the higher PCE of 5.15% in QDSSC than the Pt (1.25%).

Improving the performance of quantum dot sensitized solar cells through CdNiS quantum dots with reduced recombination and enhanced electron lifetime

Ni²⁺ doped CdS QDs in QDSSCs can suppress charge recombination, prolong the electron lifetime and improve the PCE of the cell.

One-step synthesis of solution processed time-dependent highly efficient and stable PbS counter electrodes for quantum dot-sensitized solar cells

A QDSSC with time-dependent optimized PbS CE exhibits a higherηof 4.61% than that of Pt CE (1.34%).