Self-Cleaning Performance of Super-Hydrophilic Coatings for Dust Deposition Reduction on Solar Photovoltaic Cells

Dust deposition on solar photovoltaic (PV) cell surface will significantly decrease the PV power efficiency, as the transmittance of the solar cells would be greatly decreased by the deposited dust particles. This paper aims to study the anti-dust performance of super-hydrophilic coatings for the solar PV cells with water spraying condition. The solar cell covering glass was treated to be super-hydrophilic and compared with the bare glass sample. It was found that many dust particles adhere and aggregate on the uncoated glass while the particles deposited on the super-hydrophilic glass surface are densely distributed. When the water spraying process was conducted, the dust deposition mass for the bare and the coated glass samples are both reduced obviously with the increase time of water spraying. In addtion, dust deposition mass is significantly reduced with the increase of deposition and spraying tilt angles. The self-cleaning efficiency of super-hydrophilic coating on dust deposition is 92% higher than the bare glass cases. The spectral transmittance of glass samples for all the coated cases are significantly higher than that for all the bare cases. The maximum transmittance improvement can reach 26.5% when the deposition tilt angle is 30° and the spraying tilt angle is 60°.

Superhydrophilic Smart Coating for Self-Cleaning Application on Glass Substrate

In general, superhydrophilic coating on glass substrate possesses water contact angle (WCA) below 10° and contains high self-cleaning properties in outdoor environment as compared to noncoated glass substrate panels. In this study, the superhydrophilic coating behavior on glass substrate has been developed. The micro- and nanosized titanium dioxide (TiO2) particles have been utilized to improve the surface roughness, and the polypropylene glycol (PPG) has been utilized to increase the surface energy of glass substrates. The wettability of coating surface shows the coating possess water contact angle (WCA) as low as 5° and suddenly reduce to 0° after 10 s. Superhydrophilic coated glass clearly shows excellent dirt repellent against dilute ketchup solution due to the absence of dirt streak on the glass surface. Meanwhile, the dirt streak is present on the bare glass surface indicating its weak self-cleaning property. The developed superhydrophilic coating on glass substrate was also found to have great antifog property compared to the bare glass substrate. Superhydrophilic surfaces have showed free tiny droplet even at 130°C of hot boiling bath for 10 min and completely dry after 1 min. The superhydrophilic coating surfaces have demonstrated free water streak after impacting with harsh water spraying for 5 min confirming that the superhydrophilic coating on glass substrate is antiwater streak.

TiO2 nanosheet array thin film for self-cleaning coating

A simple hydrothermal method is developed to directly grow TiO2 nanosheets on a bare glass substrate.

High Reliability and High Performance 30μm Through-Package-Vias in Ultra-Thin Bare Glass Interposer

This paper presents, for the first time, the thermo-mechanical reliability and the electrical performance of 30μm through package vias (TPVs) formed by Corning in ultra-thin low-cost bare glass interposers and metallized directly by sputter seed and electroplating. In contrast to glass interposers with polymer coated glass cores reported previously, this paper reports on direct metallization of thin and uncoated glass panels with fine pitch TPVs. The scalability of the unit processes to large panel sizes is expected to result in bare glass interposers at 2 to 10 times lower cost than silicon interposers fabricated using back end of line (BEOL) wafer processes. The thermo-mechanical reliability of 30μm TPVs was studied by conducting accelerated thermal cycling tests (TCT), with most via chains passing 1000 cycles from −55°C to 125°C. The high-frequency behavior of the TPVs was characterized by modeling, design and measurement up to 30 GHz.