用p型有机半导体材料酞菁铜作为阴极缓冲层制作了器件结构为氧化铟锡/酞菁锌/碳六十/酞菁铜/铝的有机小分子太阳能电池,对器件进行电学测量发现酞菁铜缓冲层的厚度对器件的开路电压有明显影响.基于半导体器件物理分析了光照下测量得到的电流-电压曲线,由拟合结果得到的器件参数表明高理想因子导致了器件开路电压升高,其原因为器件的输运特性不只受酞菁锌与碳六十形成的p-n结影响,还与酞菁铜缓冲层与铝电极形成的肖特基接触有关.研究表明在有机太阳能电池器件中引入一个合适的缓冲层/阴极肖特基结可以提高器件的开路电压.
The effect of copper phthalocyanine( Cu Pc) buffer layer on open circuit voltage in indium tin oxide /zinc phthalocyanine( Zn Pc) / C60 / Cu Pc / Al devices is investigated. A dependence of the open circuit voltage on the thickness of Cu Pc layer is observed. We analyze the current-voltage curves under illumination based on semiconductor device theory. A high ideality factor is found as the reason for the high open circuit voltage. We propose that both Zn Pc / C60 junction and Cu Pc / Al contact contribute the high ideality factor. Our result shows that the open circuit voltage may be improved by introducing an extra rectifying buffer / cathode junction.