Incorporating a stable fluorenone unit into D–A–π–A organic dyes for dye-sensitized solar cells
作者:Chuanjiang Qin、Ashraful Islam、Liyuan Han
DOI:10.1039/c2jm33105e
日期:——
Two new organic dyes based on a donorâacceptorâÏâbridgeâacceptor/anchor (DâAâÏâA) configuration, HIQF1 and HIQF2, were synthesized, characterized, and successfully employed in dye-sensitized solar cells. The incorporation of the weakly electron-withdrawing fluorenone group as an additional acceptor enhanced the dyes' properties for solar energy conversion in several ways. First, the absorption spectra of the dyes were broadened, covering a large range of sunlight. Second, the absorption spectra observed upon dye adsorption on TiO2 were only slightly blue-shifted as compared to the spectra of the dyes in solution. Third, the orbital energy levels and electron distributions of the DâAâÏâA backbone were ideal for highly efficient electron transport and injection. The incorporation of long electron-donating alkoxy groups in the donor unit of HIQF1 further increased the dye's short-circuit photocurrent density (Jsc), open-circuit voltage (Voc), and overall conversion efficiency (η), but had little negative effect on the fill factor (FF). Solar cells sensitized with HIQF1 showed excellent currentâvoltage characteristics; the Jsc, Voc, and FF values were 12.26 mA cmâ2, 0.70 V, and 0.73, corresponding to a η value of 6.26%.
研究人员合成了两种新型有机染料 HIQF1 和 HIQF2,它们都是基于供体-受体-桥-受体/锚(DâAâÏâA)构型,并对其进行了表征,还成功地将其应用于染料敏化太阳能电池。掺入弱电子吸收的芴酮基团作为额外的受体,从几个方面增强了染料在太阳能转换方面的性能。首先,拓宽了染料的吸收光谱,覆盖了较大的日光范围。其次,与溶液中的染料光谱相比,在二氧化钛上吸附染料后观察到的吸收光谱只有轻微的蓝移。第三,DâAâÏâA 骨架的轨道能级和电子分布非常适合高效电子传输和注入。在 HIQF1 的供体单元中加入长的电子供体烷氧基,进一步提高了染料的短路光电流密度(Jsc)、开路电压(Voc)和整体转换效率(δ-),但对填充因子(FF)几乎没有负面影响。使用 HIQF1 进行敏化的太阳能电池显示出极佳的电流电压特性;Jsc、Voc 和 FF 值分别为 12.26 mA cmâ2 、0.70 V 和 0.73,对应的 Î- 值为 6.26%。