Electrodeposition of Cu2S nanoparticles on fluorine-doped tin oxide for efficient counter electrode of quantum-dot-sensitized solar cells

A study of simultaneous electrodeposition of Cu and S in choline chloride-ethylene glycol deep eutectic solvents: a pathway to the synthesis of copper sulfide hexagons

Copper sulfides, with their tunable semiconductor properties, are promising materials for electronic and optoelectronic devices. Among the various synthesis techniques, electrodeposition stands out as a particularly effective method, offering precise control over the structure and composition of these compounds. In this study, we demonstrate the feasibility of co-electrodeposition of copper and sulfur on a carbon substrate using deep eutectic solvents (DESs) based on choline chloride and ethylene glycol. The effects of electrodeposition potential and electrochemical bath composition on the electroreduction process of CuCl2·2H2O and Na2S2O3 mixtures in DESs were investigated. By controlling the electrochemical deposition parameters, we successfully obtained various structures, including Cu clusters, S-doped Cu clusters, and copper sulfide (CuxS) hexagons. The morphology and composition of the obtained materials were characterized using scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) techniques. Our findings indicate that co-electrodeposition of Cu and S requires potentials more negative than -0.84 V vs. Pt. Furthermore, the formation of CuxS hexagons was achieved by acidifying electrochemical baths with H2SO4. Interestingly, the electrodeposition of Cu from DESs was favored under all investigated synthesis conditions. Consequently, the average atomic percentage of S in the obtained Cu-S materials was a maximum of 9.36 at%, while EDS point analyses revealed that individual copper sulfide hexagons contained 22.7 to 23.8 at% of S. These results provide valuable insights into the co-electrodeposition of Cu and S from choline chloride-ethylene glycol DESs and pave the way for the future development of novel copper sulfide-based materials.

Efficient counter electrode for quantum dot sensitized solar cells using p-type PbS@reduced graphene oxide composite

This study developed a novel PbS-rGO composite counter electrode to enhance the performance of quantum dot-sensitized solar cells (QDSSCs). The composite was synthesized via a hydrothermal method by anchoring PbS nanocubes onto reduced graphene oxide (rGO) sheets. The effect of the mass ratio of rGO to PbS (0.0, 0.1, 0.3, and 0.6) on power conversion efficiency (PCE) was investigated. The optimized rGO-PbS (0.03) composite achieved a power conversion efficiency of 5.358%, V oc of 0.540 V, J sc of 21.157 mA cm-2, and FF of 0.516. The rGO framework provides an interconnected conductive network that facilitates efficient charge transport, reduces charge transfer resistance, and improves overall conductivity. Electrochemical analyses confirmed the superior electrocatalytic activity of the composite in reducing the S n 2-/S2- redox couple. The unique band alignment between rGO and PbS optimized the electron transfer pathways. The hierarchical structure increased the surface area and light absorption, enabling a more effective charge transfer at the electrode-electrolyte interface.

Synthesis and performance evaluation of ZnO/CdS photoanodes with copper sulfide (Cu2S) and carbon counter electrodes

The present study demonstrates the synthesis of compact ZnO layers using CdS sensitized on ZnO as a photoanode with copper sulfide (Cu2S) and carbon as a counter electrode (CE). In this study, a compact ZnO layer was fabricated using the simple and low-cost successive ionic layer adsorption and reaction (SILAR) method, and Cu2S CE films were synthesized using the chemical bath deposition method. Various characterizations, such as X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), confirmed the formation of ZnO and CdS sensitizations on the ZnO . UV-visible spectroscopy revealed that the bandgaps of the ZnO and Cu2S films were 3.2 and 1.3 eV, respectively. Furthermore, the morphology of the ZnO films was optimized by varying the number of SILAR cycles. Scanning electron microscopy revealed the formation of a nanorod compact layer (CL) and the porous nature of the ZnO photoanode films. However, the porosity increased with the number of SILAR cycles. Various parameters, such as the current density, voltage, fill factor, and efficiency, were measured using the J-V characteristics. The highest 0.85% efficiency was achieved by using the ZnO compact film with 30 SILAR cycles for the Cu2S CE. Furthermore, the study revealed that the Cu2S counter electrode had a higher electrocatalytic response than the carbon CE.

Electrodeposition of Cu2NiSnS4 absorber layer on FTO substrate for solar cell applications

Potentiostatic and in situ electrochemical impedance spectroscopy (EIS) measurements were recorded to study the nucleation and growth mechanisms of electrodeposited Cu2NiSnS4 (CNTS) thin films from aqueous solution at different applied potentials. The electrodeposition process of Cu-Ni-Sn-S precursors were studied using cyclic voltammetry and chronoamperometry techniques. The nucleation and growth mechanism of these films was found to follow a three-dimensional progressive nucleation limited by diffusion-controlled growth. The nucleation mechanism is found to be influenced by the presence of S2O3 2-, which prompts the electrodeposition of S. In situ electrochemical impedance spectroscopy (EIS) investigates the electrodeposition behavior of CNTS precursors on the surface electrode. A capacitive behavior was observed at high frequencies, while the presence of Warburg diffusion was detected only for potentials less negative than -1.0 V vs. Ag/AgCl. The crystallographic structure, morphology, composition, and optical band gap of CNTS thin films was examined using X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and UV-visible spectroscopy. Electrodeposition at -0.98 V vs. Ag/AgCl resulted in the formation of microsheets with a uniform morphology and homogeneous thickness of sulfurized CNTS film. This potential also proved to be optimal for achieving higher crystallinity, a pure phase, and a suitable band gap energy of approximately 1.6 eV.

A Comprehensive Review on Perovskite Solar Cells Integrated Photo-supercapacitors and Perovskites-Based Electrochemical Supercapacitors

Perovskite solar cells (PSCs) have rapidly become a prevalent photovoltaic technology owing to their simple structure, low processing cost, and remarkable increase in solar-to-electric power conversion efficiency (PCE). However, the intermittent nature of solar radiation induces some technical and financial challenges for its practical applications as a reliable power source. To address this issue, the integration of PSCs with supercapacitors (SCs) in the form of integrated photo-supercapacitors (IPSs) has gathered significant attention. This integration can balance energy availability and demand, reduce energy wastage, and stabilize power output for portable and wearable electronics. Meanwhile, the excellent optoelectronic properties with mixed electronic and ionic conductivity of metal halide perovskites (MHPs) have expanded their application as electrode and electrolyte materials for SCs and photo-supercapacitors (PSs) applications. This review provides an all-inclusive summary of the current state-of-the-art research progress of PSCs-IPSs and MHPs-based SCs and PSs by highlighting their basics and integration approaches. It also discusses the challenges and prospects of these materials and technologies.

P-incorporated CuO/Cu2S heteronanorods as efficient electrocatalysts for the glucose oxidation reaction toward highly sensitive and selective glucose sensing

Currently, tremendous efforts have been made to explore efficient glucose oxidation electrocatalysts for enzymeless glucose sensors to meet the urgent demands for accurate and fast detection of glucose in the fields of health care and environmental monitoring. In this work, an advanced nanostructured material based on the well-aligned CuO/Cu2S heteronanorods incorporated with P atoms is successfully synthesized on a copper substrate. The as-synthesized material shows high catalytic behavior accompanied by outstanding electrical conductivity. This, combined with the unique morphology of unstacked nanorod arrays, which endow the entire material with a greater number of exposed active sites, make the proposed material act as a highly efficient electrocatalyst for the glucose oxidation reaction. Density functional theory calculations demonstrate that P doping endows P-doped CuO/Cu2S with excellent electrical conductivity and glucose adsorption capability, significantly improving its catalytic performance. As a result, a non-enzymatic glucose sensor fabricated based on our proposed material exhibits a broad linear detection range (0.02-8.2 mM) and a low detection limit (0.95 μM) with a high sensitivity of 2.68 mA mM-1 cm-2 and excellent selectivity.

Copper selenide (Cu3Se2 and Cu2-xSe) thin films: electrochemical deposition and electrocatalytic application in quantum dot-sensitized solar cells

In this work, high crystallinity copper selenide thin films directly deposited onto conducting substrates were obtained through a potentiostatic electrodeposition approach. The as-deposited copper selenides involve annealing induced phase transformation from tetragonal Cu3Se2 to cubic Cu2-xSe. The annealing also leads to a remarkable morphology change from dendritic nanosheets to connected networks and separated particle shapes for the annealed (A-Cu2-xSe) and selenized (S-Cu2-xSe) samples, respectively. The copper selenide thin films were demonstrated to serve as efficient counter electrodes (CEs) in quantum dot-sensitized solar cells (QDSCs) for electrocatalyzing polysulfide electrolyte regeneration. The CdS/CdSe QDSCs constructed with copper selenide CEs deliver considerable power conversion efficiencies (PCEs), especially an optimal value of 3.89% for the A-Cu2-xSe CE-based device. The enhanced photovoltaic performance benefits from the connected network microstructure of A-Cu2-xSe films which afford a large number of reaction sites and efficient charge transport pathways. The Tafel polarization characterization further indicates that, in contrast to the commonly used Cu2S and Pt CEs, the non-stoichiometric Cu2-xSe CE exhibits better electrochemical catalytic activity. This work highlights the great potential of electrodeposition for fabricating promising copper selenide CEs for high performance QDSCs.