改性金莲花色素敏化太阳能电池的性能研究

Improvement of Photovoltage with Modified Trollius Chinensis Pigment in Dye Sensitized Solar Cells

染料敏化太阳能电池(DSCs)中,高原天然染料敏化剂花青素由于分子中含有多个羟基基团,有助于其与TiO_2有效结合形成有效的电子注入通道,从而表现出优异的性能,但同时由于远离二氧化钛光阳极部分的羟基易吸收水分,容易增加电荷复合同时电池性能下降,因此本研究通过对花青素进行化学改性来解决该问题。首先从高原金莲花中提取天然染料,并通过紫外可见吸收光谱和红外吸收光谱测试,确定所获取的产物主要成分为花青素;在此基础上对所获得的花青素分子进行化学改性,通过酯化反应去除部分多余的羟基基团。将所获得的改性产物用于DSC中,相比于未改性的花青素敏化电池,光伏性能得到了明显的改善,开路电压提高了30 m V。

In dye-sensitized solar cells(DSCs), anthocyanins, one of the plateau natural dyes, exhibits outstanding photovoltaic performance, since it contains multiple widespread hydroxyl groups in the molecule which enables its adsorption onto the surface of TiO_2 and generation of effective electron injection channels. However, the extra hydroxyl groups that are stretching away from TiO_2 usually absorb water, leading to more serious recombination and thus destroying photovoltaic performance. Herein, chemical modification of anthocyanins was conducted to reduce the redundant hydroxyl group numbers. Firstly, trollius chinensis pigment with good purity was obtained by extraction from trollius chinensis pigment, confirmed by comprehensive optical measurements. Based on this, the modification by esterification reaction was carried out towards anthocyanins. When incorporated into solar cells, it was found that the modified products of anthocyanins resulted in obviously improved conversion efficiency compared with those based on unmodified ones, and notably the open-circuit voltage was increased by 30 mV.