Comfort Analysis of Hafnium (Hf) Doped ZnO Coated Self-Cleaning Glazing for Energy-Efficient Fenestration Application

A review of self-cleaning coatings for solar photovoltaic systems: theory, materials, preparation, and applications

Photovoltaic power generation is developing rapidly with the approval of The Paris Agreement in 2015. However, there are many dust deposition problems that occur in desert and plateau areas. Traditional cleaning methods such as manual cleaning and mechanical cleaning are unstable and produce a large economic burden. Therefore, self-cleaning coatings, which have unique mechanisms and high adaptability, have attracted wide attention in the photovoltaic industry and scientific community, especially the super-hydrophobic and super-hydrophilic coatings. The paper systematically reviewed the theory, materials, preparation, and applications of the super-hydrophobic and super-hydrophilic coatings on the photovoltaic modules. Super-hydrophobic materials such as organosilicon compounds, fluorinated polymers, and some inorganic materials are popular. TiO2 is widely used to prepare super-hydrophilic coatings on glass covers of photovoltaic panels due to its good photocatalytic activity. CVD-based surface treatment is suitable for preparing photovoltaic self-cleaning surfaces. These methods prepare self-cleaning surfaces by reacting gaseous substances with hot surfaces and depositing them on the surface. They are efficient but difficult to control accuracy. When applied to photovoltaic modules, it is crucial to consider the factors such as self-cleaning, transparency, anti-reflection, anti-icing, and durability. In future research, it is significant to improve the transparency, durability, and self-cleaning properties of coatings.

Perovskite Solar Cells: A Review of the Recent Advances

Perovskite solar cells (PSC) have been identified as a game-changer in the world of photovoltaics. This is owing to their rapid development in performance efficiency, increasing from 3.5% to 25.8% in a decade. Further advantages of PSCs include low fabrication costs and high tunability compared to conventional silicon-based solar cells. This paper reviews existing literature to discuss the structural and fundamental features of PSCs that have resulted in significant performance gains. Key electronic and optical properties include high electron mobility (800 cm2/Vs), long diffusion wavelength (>1 μm), and high absorption coefficient (105 cm−1). Synthesis methods of PSCs are considered, with solution-based manufacturing being the most cost-effective and common industrial method. Furthermore, this review identifies the issues impeding PSCs from large-scale commercialisation and the actions needed to resolve them. The main issue is stability as PSCs are particularly vulnerable to moisture, caused by the inherently weak bonds in the perovskite structure. Scalability of manufacturing is also a big issue as the spin-coating technique used for most laboratory-scale tests is not appropriate for large-scale production. This highlights the need for a transition to manufacturing techniques that are compatible with roll-to-roll processing to achieve high throughput. Finally, this review discusses future innovations, with the development of more environmentally friendly lead-free PSCs and high-efficiency multi-junction cells. Overall, this review provides a critical evaluation of the advances, opportunities and challenges of PSCs.