CdSe纳米晶/共轭聚合物太阳电池的制备与性能研究

采用有机金属液相法制备了平均粒径为5 nm的CdSe纳米微球(ns-CdSe), 并将其与共轭聚合物(MEH-PPV或P3HT)共混制备了太阳电池器件. 透射电镜(TEM)、紫外-可见吸收光谱(UV-Vis)及荧光光谱(PL)研究结果表明, CdSe纳米晶呈均匀的球状颗粒, 在近红外区具有良好的吸收和荧光性能; 加入CdSe纳米晶能够有效地淬灭共轭聚合物的荧光. 在AM1.5模拟太阳光(光强为100 mW/cm2)照射下, ns-CdSe/MEH-PPV共混体系太阳电池器件性能测试结果为: 短路电流ISC为1.56 mA/cm2, 开路电压VOC为0.75 V, 填充因子FF为34.5％, 光电转换效率η为0.40%; 对于ns-CdSe/P3HT共混体系, 其ISC为1.93 mA/cm2, VOC为0.65 V, FF为38.4%, η为0.48%.

Preparation and Properties of Solar Cell from CdSe Nanocrystals and Conjugated Polymer Composites

CdSe nanospheres(ns-CdSe) with diameters of 5 nm were prepared through an organometallic method at a relatively low temperature, by using cadmium stearate as the precursor and oleic acid as the surfactant. The TEM, UV-Vis absorption and PL spectra indicate that the CdSe nanocrystals were monodispersed nanospheres with the first exciton absorption peak at around 625 nm and the emission peak at around 652 nm. The ns-CdSe can be readily dispersed in organic solvent and form a homogeneous blend with conjugated polymers. The PL spectra of the ns-CdSe/polymer composite films show that the photoluminescence of the conjugated polymers are effectively quenched upon the addition of ns-CdSe. Solar cell were fabricated from the composites of ns-CdSe and conjugated polymers(MEH-PPV or P3HT). Under AM1.5 illumination(100 mW/cm2), the ISC, VOC, FF and η reached 1.56 mA/cm2, 0.75 V, 34.5% and 0.40% for the device from the ns-CdSe/MEH-PPV(15∶1 mass ratio) and 1.93 mA/cm2, 0.65 V, 38.4% and 0.48% for the device from the ns-CdSe/P3HT(10∶1 mass ratio) respectively.