Three metallophthalocyanine derivatives with different central metallocores (MPcXs, X = (OC₈H₁₇OPyCH₃I)₈), namely, ZnPcX, VOPcX, and TiOPcX, were synthesized and applied as a cathode interlayer (CIL) in the PTB7:PC₇₁BM based polymer solar cells (PSCs). Power conversion efficiency (PCE) values reached 8.1% for the devices with Ag as the cathode, while the PCE values could reach 8.2% for the devices with Al as the cathode. Moreover the three MPcXs led to similar device performance in the PSCs with either Ag or Al as the cathode. It indicates that central metallocores in the MPcXs have a negligible effect on the device performance. Working mechanism of the MPcX as the CIL in the PSCs has been investigated by photoemission spectroscopy. Findings of ultraviolet photoemission spectroscopy (UPS) and X-ray photoemission spectroscopy (XPS) demonstrated that the MPcX as the CIL not only decreased work function of the metal cathode and electron extraction barrier from PC₇₁BM to cathode but also functioned as a buffer layer to protect the active layer from the damages during the thermal deposition of Al and Ag.

中文翻译：

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用光发射光谱法研究金属酞菁衍生物作为聚合物太阳能电池阴极中间层的工作机理

合成了具有不同中心金属核（MPcXs，X =（OC ₈ H ₁₇ OPyCH ₃ I）₈）的三种金属酞菁衍生物，即ZnPcX，VOPcX和TiOPcX，并将其用作PTB7：PC _71中的阴极中间层（CIL）基于BM的聚合物太阳能电池（PSC）。以Ag为阴极的器件的功率转换效率（PCE）值达到8.1％，而以Al为阴极的器件的PCE值可以达到8.2％。此外，在以Ag或Al为阴极的PSC中，三种MPcX导致了类似的器件性能。这表明MPcX中的中央金属核对设备性能的影响可以忽略不计。通过光发射光谱法研究了MPcX作为PSC中CIL的工作机理。紫外光发射光谱法（UPS）和X射线光发射光谱法（XPS）的发现表明，作为CIL的MPcX不仅降低了金属阴极的功函数和PC _71的电子提取势垒BM至阴极，但也用作缓冲层，以保护活性层免受Al和Ag热沉积过程中的损坏。