Enhanced open-circuit voltage in polymer solar cells

We reported that the open-circuit voltage (VOC) of polymer solar cells (PSCs) can be enhanced by 0.3 V via inserting a thin layer of alcohol/water-soluble polyelectrolyte between the active layer and metal electrode. The origin of the increase in VOC can be attributed to the superposition of the built-in field with the interfacial dipole of the interlayer, and the existence of the interlayer as a dielectric was confirmed by ac impedance spectroscopy. The significant enhancement in VOC and the simplicity of incorporation of interlayer by solution processing make this method a good candidate for further enhancing the performance of PSCs.