Laboratoire de Photonique et Interfaces, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015, Lausanne, Switzerland.
ACS Nano. 2012 Apr 24;6(4):3092-9. doi: 10.1021/nn2048153. Epub 2012 Mar 21.
Solid state PbS quantum dots (QDs)/TiO(2) heterojunction solar cells were produced by depositing PbS QDs on a 500 nm thick mesoscopic TiO(2) films using layer-by-layer deposition. Importantly, the PbS QDs act here as photosensitizers and at the same time as hole conductors. The PbS QDs/TiO(2) device produces a short circuit photocurrent (J(sc)) of 13.04 mA/cm(2), an open circuit photovoltage (V(oc)) of 0.55 V and a fill factor (FF) of 0.49, corresponding to a light to electric power conversion efficiency (η) of 3.5% under AM1.5 illumination. The electronic processes occurring in this device were investigated by transient photocurrent and photovoltage measurements as well as impedance spectroscopy in the dark and under illumination. The investigations showed a high resistivity for the QD/metal back contact, which reduces drastically under illumination. EIS also indicated a shift of the depletion layer capacitance under illumination related to the change of the dipole at this interface.
采用层层自组装的方法，将 PbS 量子点（QD）沉积在 500nm 厚的介孔 TiO2 薄膜上，制备了 PbS QD/TiO2 异质结太阳能电池。重要的是，PbS QD 在这里既可以作为敏化剂，同时又可以作为空穴传输体。该 PbS QD/TiO2 器件的短路光电流（J(sc)）为 13.04mA/cm(2)，开路光电压（V(oc)）为 0.55V，填充因子（FF）为 0.49，在 AM1.5 光照下的光电转换效率（η）为 3.5%。通过瞬态光电流和光电压测量以及在黑暗和光照下的阻抗谱研究了该器件中的电子过程。研究表明，QD/金属背接触的电阻很高，在光照下会急剧降低。EIS 还表明，在光照下，与该界面处偶极子的变化相关的耗尽层电容发生了偏移。
