通过Alq3∶CsF复合阴极缓冲层来优化CuPc/C60有机小分子太阳能电池的性能。 当Alq3∶CsF厚度为5 nm, CsF的掺杂比例为4% 时, 加入复合阴极缓冲层器件较Alq3阴极缓冲层器件的能量转化效率提高了49%, 到达0.76%, 并且在室温、 大气的条件下, 器件的稳定性也得到了保持, 与未加阴极缓冲层的器件相比, 半衰期提高了6倍, 达到9.8 h。 通过紫外-可见吸收、 外量子效率和单载流子传输器件等研究了器件效率改善的主要原因是掺入CsF后, 调节界面能级, 改善了Alq3的电子传输特性, 提高了器件的短路电流和填充因子。 比较分析复合阴极缓冲层器件于空气中放置不同的时间的电流电压曲线, 表明Alq3∶CsF可以保持Alq3的良好稳定性, 可以很好地阻挡氧气与水分的扩散, 提高器件的寿命。

This paper introduces the methods improving the performance and stability of copper-phthalocyanine(CuPc)/ fullerene(C60) small molecule solar cells by using tris-(8-hydroxyquinoline)aluminum(Alq3): cesium fluoride(CsF) composite cathode buffer layer. The device with Alq3∶CsF composite cathode buffer layer with a 4 wt.% CsF at a thickness of 5 nm exhibits a power conversion efficiency (PCE) of up to 0.76%, which is an improvement of 49%, compared to a device with single Alq3 cathode buffer layer and half-lifetime of the cell in air at ambient circumstance without any encapsulation is almost 9.8 hours, 6 times higher than that of without buffer layer, so the stability is maintained. The main reason of the device performance improvement is that doping of CsF can adjust the interface energy alignment, optimize the electronic transmission characteristics of Alq3 and improve the short circuit current and the fill factor of the device using ultraviolet-visible absorption, external quantum efficiency and single-electron devices. Placed composite cathode buffer layer devices with different time in the air, by comparing and analyzing current voltage curve, Alq3∶CsF can maintain a good stability as Alq3. Alq3∶CsF layer can block the diffusion of oxygen and moisture so completely as to improve the lifetime of the device.