Boosting the photovoltaic performance of CdS/P3HT solar cells by Mn inclusion

This study highlights the enhancement in efficiency for CdS:Mn-based hybrid photovoltaic cells. Morphological analysis demonstrated that the inclusion of Mn resulted in a reduction in the grain size of CdS films. Notably, while solar cells using pure CdS and CdS:Mn (1%) films showed individual P3HT coverage on the grains, the device with 2% Mn-doping achieved a uniform surface coating. Mn incorporation significantly increased the transparency of the devices, especially in the near-infrared region, leading to a corresponding decrease in their absorbance. Photoluminescence (PL) measurements demonstrated that the P3HT layer largely dominated the emission spectra across all devices. However, Mn-doped CdS-based cells exhibited lower PL peak intensity than the reference device, suggesting more efficient exciton dissociation at the CdS:Mn/P3HT interface of the devices. Electrical characterization further confirmed that Mn-doping improved the conversion efficiency (ƞ), with the highest ƞ of 0.019% observed for the ITO/CdS:Mn (2%)/N719/P3HT device.