缓冲夹层影响异质结有机光伏器件性能研究

制备了结构为CuPc/缓冲层/C60异质结的有机光伏器件,分别选用三氧化钼和红荧烯为缓冲层,研究了增加缓冲层对器件性能的影响.结果表明,增加三氧化钼和红荧烯缓冲层后器件的开路电压和光电转换效率都得到提高,器件的短路电流密度和填充因子都有所降低.开路电压从没有缓冲层时的0.39V分别提高到0.58V、0.55V,转换效率从0.36%提高到0.44%,短路电流从1.92mA/cm2分别降低到1.77mA/cm2、1.81mA/cm2,填充因子从0.48分别减少到0.43、0.44.进一步研究表明器件的短路电流密度受缓冲层厚度的影响很大,当缓冲层厚度很小时,器件短路电流密度还有所增加,但随着缓冲层厚度的增加,短路电流密度逐渐减小,当缓冲层厚度为10nm时,器件短路电流密度减少到0.35mA/cm2.开路电压随着厚度的增加逐渐增加,从1nm时的0.43V增加10nm时0.63V.根据整数电荷转移模型和界面能级理论解释有机光伏器件开路电压提高以及短路电流密度减少的原因,为有机太阳能电池性能的改善提供了研究方法.

Impact of Buffer Interlayer on the Performance of Heterojunction Organic Photovoltaic Devices

The CuPc/buffer interlayer/C60 heterojunction organic photovoltaic devices are fabricated by inserting a MoO3 or RB interlayer and investigated the impact of buffer interlayer on the performance of heterojunction organic photovoltaic devices. The results suggest that OPV with the buffer interlayer has higher open-circuit voltage and power conversion efficiency, lower short-circuit current density and fill factor. The open-circuit voltage increases from 0.39 V to 0.58 V and 0.55 V, respectively, and the power conversion efficiency reaches 0.44%, in comparison with a power conversion efficiency of 0.36% for OPV without interlayer. The short-circuit current density decreases from 1.92 mA/cm2 to 1.77 mA/cm2 and 1.81 mA/cm2, and from 0.48 to 0.43 and 0.44 in fill factor, respectively. Further research shows that the short-circuit current density strongly depends on the thickness of buffer layer. The short-circuit current density increases when the interlayer thickness is small, while it gradually decreases as the buffer layer thickness increasing. When the interlayer thickness is 10 nm, the short-circuit current density decreases to 0.35 mA/cm2. The open-circuit voltage enhances as the buffer layer thickness increasing, from 0.43 V with 1 nm interlayer to 0.63 V 10 nm interlayer. Open-circuit voltage enhancement and the short-circuit current density decrease are studied according to the integer charge transfer model and interfacial energy level theory, which provide a research foundation for the performance improvement of organic solar cells.