中草药天然染料敏化剂的光电性能

The photoelectrical properties of natural dye sensitizers of Chinese medicinal herbs

从野菊花、石榴皮、车前草和紫草四种常见的中草药中提取天然染料,并作为敏化剂将其应用于染料敏化太阳电池(DSC),分别考察提取方法、天然染料浓度和中草药类型对器件光电性能的影响。在所考察的四种中草药天然染料中,短路电流和转换效率从高到低均依次为野菊花、石榴皮、车前草和紫草。煎煮法比乙醇浸提法更适合用于提取DSC敏化剂的野菊花天然染料,前者获得的野菊花天然染料的短路电流和转换效率分别达到后者的1·29倍和1·6倍。当采用野菊花天然染料作为敏化剂时,染料浓度1%是关键临界点,短路电流和转换效率在浓度小于1%时均急剧增加,在浓度为1%-10%之间时均缓慢增加,而转换效率在浓度到达20%时反而稍有下降。

Nature dyes extracted from four common Chinese medicinal herbs, namety wild chrysanthemum, granatum, plantain and gromwell, were applied as sensitizers in dye- sensitized solar cells （DSC） . The photoelectrical properties of the cells were systemati- cally investigated as a function of extract method, dye concentration and herb type. Among four Chinese medicinal herbs dye sensitized solar cell, the chrysanthemum has the best short circuit current and efficiency, followed by the granatum, the plantain and the groin- well. And decocting method is better fit for extracting dye from chrysanthemum than ethanol extraction method. The efficiency of the former method extracted dye is 60% higher than that of the latter method extracted dye. Furthermore, when using chrysanthemum derived dye as sensitizer for DSC, the dye concentration of 1% is a critical point. Both short - circuit current density and efficiency increase evidently as the dye concentration ascends to 1%, then turn to climb slowly as the dye concentration increases from I% to 10%.