Influence of Weak Base Addition to Hole-Collecting Buffer Layers in Polymer:Fullerene Solar Cells
Influence of Weak Base Addition to Hole-Collecting Buffer Layers in Polymer:Fullerene Solar Cells
Blog Article
We report the effect of weak base addition to acidic polymer hole-collecting Gift Card layers in normal-type polymer:fullerene solar cells.Varying amounts of the weak base aniline (AN) were added to solutions of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS).The acidity of the aniline-added PEDOT:PSS solutions gradually decreased from pH = 1.
74 (AN = 0 mol% ) to pH = 4.24 (AN = 1.8 mol %).
The electrical conductivity of the PEDOT:PSS-AN films did not change much with the pH value, while the ratio of conductivity between out-of-plane and in-plane directions was dependent on the pH of solutions.The highest power ICL Thermistor conversion efficiency (PCE) was obtained at pH = 2.52, even though all devices with the PEDOT:PSS-AN layers exhibited better PCE than those with the pristine PEDOT:PSS layers.
Atomic force microscopy investigation revealed that the size of PEDOT:PSS domains became smaller as the pH increased.The stability test for 100 h illumination under one sun condition disclosed that the PCE decay was relatively slower for the devices with the PEDOT:PSS-AN layers than for those with pristine PEDOT:PSS layers.