Efficient FAPbI3–PbS quantum dot graphene-based phototransistors

PbS quantum dots capped with formamidinium ligands were deposited as graphene-based photodetectors. Solid phase exchange improves the infrared photo-detectivity.

Electrochemical Fingerprint of CuS-Hexagonal Chemistry from (Bis(N-1,4-Phenyl-N-(4-Morpholinedithiocarbamato) Copper(II) Complexes) as Photon Absorber in Quantum-Dot/Dye-Sensitised Solar Cells

The main deficit of quantum dot/dye-sensitised solar cells (QDSSCs) remains the absence of a photosensitiser that can absorb the entire visible spectrum and increase electrocatalytic activity by enhancing the conversion efficiency of QDSSCs. This placed great emphasis on the synthesis route adopted for the preparation of the sensitiser. Herein, we report the fabrication of hexagonal copper monosulfide (CuS) nanocrystals, both hexadecylamine (HDA) capped and uncapped, through thermal decomposition by thermogravimetric analysis (TGA) and a single-source precursor route. Morphological, structural, and electrochemical instruments were used to assert the properties of both materials. The CuS/HDA photosensitiser demonstrated an appropriate lifetime and electron transfer, while the electron back reaction of CuS lowered the electron lifetime in the QDSSCs. The higher electrocatalytic activity and interfacial resistance observed from current density-voltage (I–V) results agreed with electrochemical impedance spectroscopy (EIS) results for CuS/HDA. The successful fabrication of hexagonal CuS nanostructures of interesting conversion output suggested that both HDA capped and uncapped nanocrystals could be adopted in photovoltaic cells.

A frontier Zn- and N-rich complex grafted onto reduced graphene oxide for the electrocatalysis of dye-sensitized solar cells

A soluble small molecule nitrogen-rich zinc-organic framework for a graphene-based high-efficiency electrocatalytic electrode.

Major Impediment to Highly Efficient, Stable and Low-Cost Perovskite Solar Cells

Organic–inorganic hybrid perovskite solar cells (PSCs) have made immense progress in recent years, owing to outstanding optoelectronic properties of perovskite materials, such as high extinction coefficient, carrier mobility, and low exciton binding energy. Since the first appearance in 2009, the efficiency of PSCs has reached 23.3%. This has made them the most promising rival to silicon-based solar cells. However, there are still several issues to resolve to promote PSCs’ outdoor applications. In this review, three crucial aspects of PSCs, including high efficiency, environmental stability, and low-cost of PSCs, are described in detail. Recent in-depth studies on different aspects are also discussed for better understanding of these issues and possible solutions.

Influence of solvents in the preparation of cobalt sulfide for supercapacitors

In this study, cobalt sulfide (CoS) electrodes are synthesized using various solvents such as water, ethanol and a combination of the two via a facile chemical bath deposition method on Ni foam. The crystalline nature, chemical states and surface morphology of the prepared CoS nanoparticles are characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transition electron microscopy. The electrochemical properties of CoS electrodes are also evaluated using cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. When used as an electrode for a supercapacitor, CoS prepared with ethanol as a solvent exhibits a capacitance of 41.36 F g^-1 at 1.5 A g^-1, which is significantly better than that prepared using water and water/ethanol-based solvents (31.66 and 18.94 F g^-1 at 1.5 A g^-1, respectively). This superior capacitance is attributed to the ideal surface morphology of the solvent, which allows for easy diffusion of electrolyte ions into the inner region of the electrode. High electrical conduction enables a high rate capability. These results suggest that CoS nanoparticles are highly promising for energy storage applications as well as photocatalysis, electrocatalysis, water splitting and solar cells, among others. These results show that CoS is a promising positive electrode material for practical supercapacitors.

Efficient Dye-Sensitized Solar Cells Based on Nanoflower-like ZnO Photoelectrode

A photoanode material ZnO nanoflower (ZNFs) for efficient dye-sensitized solar cell (DSSC) was prepared. This unique structure can significantly increase the specific surface area and amount of light absorption, leading to a higher short-circuit current density. Furthermore, ZNFs resulted in closer spacing between the nanorods and more direct conduction paths for electrons, leading to higher open-circuit voltage. The overall promising power conversion efficiency of 5.96% was obtained with photoanodes of 8.5 μm thickness. This work shows that ZNFs is an attractive material and has good potential for application in high efficiency ZnO-based DSSCs.

ZnS quantum dots impregnated-mesoporous TiO2 nanospheres for enhanced visible light induced photocatalytic application

ZnS quantum dots were impregnated on the surface of TiO₂ mesospheres by a soft template-assisted solvothermal approach.

An innovative catalyst design as an efficient electro catalyst and its applications in quantum-dot sensitized solar cells and the oxygen reduction reaction for fuel cells

Highly-efficient Co_90%Ni_10% catalytic nanostructures on FTO and Ni-foam show high performance in QDSSCs and fuel cells.

Densely packed zinc sulfide nanoparticles on TiO2 for hindering electron recombination in dye-sensitized solar cells

A graphical diagram of DSSCs without and with ZnS as a compact layer on a TiO₂ film.

The effect of TiO2 nanoflowers as a compact layer for CdS quantum-dot sensitized solar cells with improved performance

Currently, TiO2 on a fluorine-doped tin oxide substrate is the most commonly used type of photoelectrode in high-efficiency quantum dot-sensitized solar cells (QDSSCs). The power conversion efficiency (PCE) of TiO2 photoelectrodes is limited because of higher charge recombination and lower QD loading on the TiO2 film. This article describes the effect of a TiO2 compact layer on a TiO2 film to enhance the performance of QDSSCs. TiO2 nanoparticles were coated on an FTO substrate by the doctor-blade method and then the TiO2 compact layer was successfully fabricated on the surface of the nanoparticles by a simple hydrothermal method. QDSSCs were made using these films as photoelectrodes with NiS counter electrodes. Under one sun illumination (AM 1.5 G, 100 mW cm(-2)), the QDSSCs showed PCEs of 2.19 and 2.93% for TCL1 and TCL2 based photoelectrodes, which are higher than the 1.33% value obtained with bare TiO2. The compact-layer-coated film electrodes provide a lower charge-transfer resistance and higher light harvesting. The compact layer on the TiO2 film is a more efficient photocatalyst than pure TiO2 film and physically separates the injected electrons in the TiO2 from the positively charged CdS QD/electrolyte.