Preparation And Performance Of SiO₂and Eu³⁺ Doped SiO₂Antireflective Films

One of the effectest ways that improve the photoelectric conversion efficiency of solar cell is to coating an antireflective film on photovoltaic glass module, Our approach is then fabricating high-effective antireflective films by Sol-Gel method.Antireflective film was researched based on commercial SiO2coating solution. By using polyvinyl alcohol (1788-PVA) as pore foemer, these parameters just like the concentration of SiO2sol and polyvinyl alcohol (1788-PVA),annealing temperature, pH value and aging time, were studied in this experiment. The results showed that commercialized SiO2aqueous sol which was adjusted to6.0%, the content of polyvinyl alcohol (PVA-1788) for3wr%, the coating solution at pH value of10.0was the stablest one, could be stored for eight months at room temperature, then the gel film was preserved for10min at450℃, the micro structure of thin film had well light-penetrated "moth eye" structure, showed a more than a4.6%increase in optical trans mittance.Secondly, Eu3+doped SiO2antireflective film was fabricated and studied. Just for using effectively visible light, rare-earth europium was used as light conversion agent to further improve the photoelectric conversion efficiency of solar cells. This study first prepared of the Eu3+doped SiO2sol via sol-gel method, the micro structure analysis of TEM indicated that Eu3+was evenly distributed in the sol particles, the fluorescence spectra test of Eu3+doped SiO2powder revealed the concentration of Eu3+and the increase of alcohol/water ratio caused the fluorescence quenching, The TEOS/ethanol/water molar ratio of sol was1:15:35with Eu3+concentration of0.8%g/mL, the luminance properties of the powder was the best. And added Eu3+doped SiO2sol into the preceding SiO2coating solution according to the ratio of0.2～10.0:90.0～99.8wt%, formed a stable Eu3+doped SiO2coating solution system as long as four months at room temperature, when the mixing ratio was1.8:98.2wt%, the Eu3+doped SiO2thin films transmittance was as high as90%, which has a more than4.26%increase, and fluorescence intensity was the highest, fluorescence spectrum presented the characteristic emission peak at614nm wavelength, corresponding to the transition from blue to red light (the5Do-7F2electron transition mode). In mechanical characteristics, the pencil hardness of SiO2and Eu3+doped SiO2antireflective film were above3H, the hardness value of nanoindentation test is0.003Gpa, Adhesion of all films went through the transparent tape and alcohol cotton wiping tests, which met the requirements of industrial production. In the contact angle test, water contact angle of SiO2thin film without Eu3+is69.5°,water contact angle of Eu3+doped SiO2antireflective film decreased significantly to19.9°, exhibits hydrophily, indicates Eu3+doped SiO2antireflective film has potential resistance to tarnish.