Towards green, efficient and stable quantum-dot-sensitized solar cells through nature-inspired biopolymer modified electrolyte

Review of recent progress in the development of electrolytes for Cd/Pb-based quantum dot-sensitized solar cells: performance and stability

Quantum dot-sensitized solar cells (QDSSCs) represent an exciting advancement in third-generation photovoltaic solar cells owing to their ability to generate multiple electron-hole pairs per photon, high stability under light and moisture exposure, and flexibility in size and composition tuning. Although these cells have achieved power conversion efficiencies exceeding 15%, there remains a challenge in enhancing both their efficiency and stability for practical large-scale applications. Therefore, in this review, we aimed to investigate recent progress in improving the long-term stability, analyzing the impact of advanced quantum dot properties on charge-transport optimization, and assessing the role of interface engineering in reducing recombination losses to maximize QDSSC performance and stability. Additionally, this review delves into key elements such as the electrolyte composition, ionic conductivity, and compatibility with counter electrodes and photoanodes to understand their influence on power conversion efficiencies and stability. Finally, potential directions for advancing QDSC development in future are discussed to provide insights into the obstacles and opportunities for achieving high-efficiency QDSSCs.

g-C3N4@TiO2 photoanodes for high-efficiency QDSSCs: improved electron transfer and photochemical stability

In QDSSCs, a photoanode is an important part of connecting the external circuit, providing support for the transmission of photogenerated carriers to the external circuit, and also providing an attachment site for QDs. In this study, we prepared a g-C3N4@TiO2 composite for the photoanode by a two-step process. The results show that the use of g-C3N4@TiO2 greatly increases the specific surface area of the material, effectively inhibits the "electron-hole" recombination, and optimizes the stability and catalytic performance of the photoanode. Among them, the cell equipped with the g-C3N4@TiO2 photoanode has improved performance: Jsc = 26.5 mA cm-2, PCE = 8.2%, Voc = 0.62 eV, and FF = 0.50. Based on the research in this paper, it can be seen that the g-C3N4@TiO2 composite applied to the photoanode can effectively improve the cell performance and provide a feasible idea for optimizing QDSSCs.

Development of Two-Dimensional Functional Nanomaterials for Biosensor Applications: Opportunities, Challenges, and Future Prospects

New possibilities for the development of biosensors that are ready to be implemented in the field have emerged thanks to the recent progress of functional nanomaterials and the careful engineering of nanostructures. Two-dimensional (2D) nanomaterials have exceptional physical, chemical, highly anisotropic, chemically active, and mechanical capabilities due to their ultra-thin structures. The diversity of the high surface area, layered topologies, and porosity found in 2D nanomaterials makes them amenable to being engineered with surface characteristics that make it possible for targeted identification. By integrating the distinctive features of several varieties of nanostructures and employing them as scaffolds for bimolecular assemblies, biosensing platforms with improved reliability, selectivity, and sensitivity for the identification of a plethora of analytes can be developed. In this review, we compile a number of approaches to using 2D nanomaterials for biomolecule detection. Subsequently, we summarize the advantages and disadvantages of using 2D nanomaterials in biosensing. Finally, both the opportunities and the challenges that exist within this potentially fruitful subject are discussed. This review will assist readers in understanding the synthesis of 2D nanomaterials, their alteration by enzymes and composite materials, and the implementation of 2D material-based biosensors for efficient bioanalysis and disease diagnosis.

Composition, Morphology, and Interface Engineering of 3D Cauliflower-Like Porous Carbon-Wrapped Metal Chalcogenides as Advanced Electrocatalysts for Quantum Dot-Sensitized Solar Cells

Designing a low-cost, highly efficient, and stable electrocatalyst that can synergistically speed up the reduction of polysulfide electrolytes while operative for long periods in the open air is critical for the practical application of quantum dot-sensitized solar cells (QDSSCs), but it remains a challenging task. Herein, a simple, straightforward, and two-step nanocomposite engineering approach that simultaneously combines metallic copper chalcogenides (MC) either Cu_{2- x} S or Cu_{2- x} Se with S, N dual-doped carbon (SNC) sources for devising high-quality counter electrode (CE) film are reported. First, the hierarchically assembled MC nanostructures are obtained using microwave-assisted synthesis. Second, these MCs are embedded within an ordered macro-meso-microporous carbon matrix to obtain Cu_{2- x} S@C or Cu_{2- x} SeS@C CE. These CEs are demonstrated to have composition dependents crystal structure, surface morphologies, photovoltaic performance, and electrochemical properties. In terms of power conversion efficiency (PCE), the Cu_{2- x} SeS@C (9.89%) and Cu_{2- x} S@C-CE (8.96%) constructed QDSSCs outperform both Cu_{2- x} Se (8.96%) and Cu_{2- x} S-constructed (7.79%) QDSSCs, respectively. The enhanced PCE could be attributed to the synergistic interaction of S and N dopants with MC interfaces that can not only enrich electric conductivity, and a higher surface-to-volume ratio but also offers a 3D network for superior charge transport at the interface.

A Novel Photoelectrochemical Sensor Based on SiNWs@PDA for Efficient Detection of Myocardial Infarction

Based on the necessity and urgency of Cardiac Troponin I (cTnI) detection for the diagnosis of myocardial infarction, a novel unlabeled photoelectrochemical (PEC) immunosensor was developed to detect cTnI rapidly...