TiO2 Passivation Layer on ZnO Hollow Microspheres for Quantum Dots Sensitized Solar Cells with Improved Light Harvesting and Electron Collection

Assemble of porous heterostructure thin film through CuS passivation for efficient electron transport in dye-sensitized solar cells

Three different modified solar cells have been passivated with copper sulfide (CuS) on a TiO2 electrode and manganese sulfide (γ-MnS) hexagonal as photon absorbers. The MnS were prepared using (a-c) bis(N-Piperl-N-p-anisildithiocarbamato)Manganese(II) Complexes Mn[N-Piper-N-p-Anisdtc] as (MnS_1), N-p-anisidinyldithiocarbamato Mn[N-p-anisdtc] as (MnS_2) and N-piperidinyldithiocarbamato Mn[N-piperdtc] as (MnS_3). The corresponding passivated films were denoted as CM-1, CM-2, and CM-3. The influence of passivation on the structural, optical, morphological, and photochemical properties of the prepared devices has been investigated. Raman spectra show that the combination of this heterostructure is triggered by the variation in particle size and surface effect, thus resulting in good electronic conductivity. The narrow band gaps could be attributed to good interaction between the passivative materials on the TiO2 surface. CM-2 cells, stability studies show that the cell is polarized and current flows due to electron migration across the electrolyte and interfaces at this steady state. The cyclic voltammetry (CV) curve for the CM-3 with the highest current density promotes the electrocatalytic activity of the assembled solar cell. The catalytic reactions are further confirmed by the interfacial electron lifetimes in the Bode plots and the impedance spectra. The current-voltage (J-V) analysis suggests that the electrons in the conduction band of TiO2/CuS recombine with the semiconductor quantum dots (QDs) and the iodolyte HI-30 electrolyte, resulting in 5.20-6.85% photo-conversions.

Improving the Conversion Ratio of QDSCs via the Passivation Effects of NiS

To revolutionize the photochemical efficiency of quantum dots sensitized solar cells (QDSSCs) devices, herein, a passivation of the cells with multilayer material has been developed for heterojunctions TiO2/NiS/MnS/HI-30/Pt devices. In this study, NiS and MnS were deposited on a photoanode for the first time as passivated photon absorbers at room temperature. The adoption of NiS as a passisvative layer could tailor the active surface area and improve the photochemical properties of the newly modified cells. The vibrational shifts obtained from the Raman spectra imply that the energy change is influenced by the surface effect, giving rise to better electronic conductivity. The electrochemical stability and durability test for the N/M-3 device slows down and remains at 8.88% of its initial current after 3500 s, as compared to the N/M-1 device at 7.20%. The disparity in charge recombination implies that both the outer and inner parts of the nanoporous material are involved in the photogeneration reaction. The hybridized N/M-3 cell device reveals the highest current density with a low potential onset, indicating that power conversion occurs more easily because photons tend to be adsorbed easily on the surface of the MnS. The Nyquist plot for N/M-1 and N/M-3 promotes the faster transport of electrolytic ions across the TiO2/NiS/MnS, providing a good interaction for the electrolyte. The I-J Value of 9.94% shows that the passivation with the NiS layer promotes electron transport and enhances the performance of the modified cells. The passivation of the TiO2 layer with NiS attains a better power conversion efficiency among the scant studies so far on the surface passivation of QDSCs.

Improved Performance of QDSSCs Can Be Achieved by Constructing a Transparent Anatase TiO2@MWCNT Photoanode Based on the Bionic Mountain Lotus

In this research, the structural characteristics of the mountain holly leaf were emulated. It was observed that after the initially uneven surface of the petals is filled with infiltrated water, it exhibits a distinctive transparent beauty after rainfall. Furthermore, the presence of leaf veins enhances the structural strength of the petals and facilitates nutrient transport. Inspired by previous studies on double-layer spin-coated films, we further developed and designed the TA TiO2@MWCNT photocathode thin film. This innovative film incorporates multiwalled carbon nanotubes (MWCNT) into a previously established TA TiO2 photocathode thin film. The inclusion of MWCNT results in the formation of a three-dimensional highway structure, where MWCNT intertwines within the TA TiO2 film. Under the operational state of immersion in the electrolyte, it maintains a level of transparency similar to that of the TA TiO2 photoanode thin film. The high-temperature sintering process results in the oxidation and depletion of MWCNTs on the surface of the film, leaving behind uniformly dispersed concave defects, thereby greatly enhancing the specific surface area. The findings demonstrate that the optoelectrode of high transparency and high specific surface area, TA TiO2@MWCNT, comprehensively enhances the performance of the solar cells. The transparent QDSSC surpasses its counterparts for the first time, achieving a power conversion efficiency (PCE) of 6.335%. This sets the stage for new materials and innovative approaches in the field of solar cells and other titanium dioxide film-related areas.

Recent advancement in quantum dot-based materials for energy storage applications: a review

The need for energy storage and conversion is growing as a result of the worsening consequences of climate change and the depletion of fossil fuels. Energy conversion and storage requirements are rising as a result of environmental problems including global warming and the depletion of fossil fuels. The key to resolving the energy crisis is anticipated to be the quick growth of sustainable energy sources including solar energy, wind energy, and hydrogen energy. In this review, we have focused on discussing various quantum dots (QDs) and polymers or nanocomposites used for SCs and have provided examples of each type's performance. Effective QD use has really led to increased performance efficiency in SCs. The use of quantum dots in energy storage devices, batteries, and various quantum dots synthesis have all been emphasized in a number of great literature articles. In this review, we have homed in on the electrode materials based on quantum dots and their composites for storage and quantum dot based flexible devices that have been published up to this point.

Synthesis and applications of TiO2/ZnO hybrid nanostructures by ZnO deposition on TiO2 nanotubes using electrochemical processes

In recent years, TiO2/ZnO hybrid nanostructures have been attracting the interest of the scientific community due to their excellent photoelectrochemical properties. The main advantage of TiO2/ZnO hybrid nanostructures over other photocatalysts based on semiconductor materials lies in their ability to form heterojunctions in which the valence and conduction bands of both semiconductors are intercalated. This factor produces a decrease in the band gap and the recombination rate and an increase in the light absorption range. The aim of this review is to perform a revision of the main methods to synthesise TiO2/ZnO hybrid nanostructures by ZnO deposition on TiO2 nanotubes using electrochemical processes. Electrochemical synthesis methods provide an easy, fast, and highly efficient route to carry out the synthesis of nanostructures such as nanowires, nanorods, nanotubes, etc. They allow us to control the stoichiometry, thickness and structure mainly by controlling the voltage, time, temperature, composition of the electrolyte, and concentration of monomers. In addition, a study of the most promising applications for TiO2/ZnO hybrid nanostructures has been carried out. In this review, the applications of dye-sensitised solar cell, photoelectrocatalytic degradation of organic compounds, photoelectrochemical water splitting, gas sensors, and lithium-ion batteries have been highlighted.

ZnO nanostructured materials for emerging solar cell applications

Zinc oxide (ZnO) has been considered as one of the potential materials in solar cell applications, owing to its relatively high conductivity, electron mobility, stability against photo-corrosion and availability at low-cost. Different structures of ZnO materials have been engineered at the nanoscale, and then applied on the conducting substrate as a photoanode. On the other hand, the ZnO nanomaterials directly grown on the substrate have been attractive due to their unique electron pathways, which suppress the influence of surface states typically found in the former case. Herein, we review the recent progress of ZnO nanostructured materials in emerging solar cell applications, such as sensitized and heterojunction architectures, including those embedded with promising perovskite materials. The remarkable advancement in each solar cell architecture is highlighted towards achieving high power conversion efficiency and operational stability. We also discuss the foremost bottleneck for further improvements and the future outlook for large-scale practical applications.

Investigating Various Permutations of Copper Iodide/FeCu Tandem Materials as Electrodes for Dye-Sensitized Solar Cells with a Natural Dye

This work presents the synthesis and deposition of CuI and FeCu materials on copper substrates for dye-sensitized solar cell applications. FeCu is a metastable alloy of iron and copper powders and possesses good optical and intrinsic magnetic properties. Coupled with copper iodide as tandem layers, the deposition of these two materials was permutated over a pure copper substrate, characterized and then tested within a solar cell. The cell was sensitized with a natural dye extracted from a local desert plant (Calotropis gigantea) and operated with an iodine/triiodide electrolyte. The results show that the best layer arrangement was Cu/FeCu/CuI, which gave an efficiency of around 0.763% (compared to 0.196% from reported cells in the literature using a natural sensitizer).