Improving the performance of perovskite solar cells with glycerol-doped PEDOT：PSS buffer layer

In this paper, we investigate the effects of glycerol doping on transmittance, conductivity and surface morphology of poly（3,4-ethylene dioxythiophene）：poly（styrene sulfonate））（PEDOT：PSS） and its influence on the performance of perovskite solar cells.. The conductivity of PEDOT：PSS is improved obviously by doping glycerol. The maximum of the conductivity is 0.89 S/cm when the doping concentration reaches 6 wt%, which increases about 127 times compared with undoped. The perovskite solar cells are fabricated with a configuration of indium tin oxide（ITO）/PEDOT：PSS/CH_3NH_3PbI_3/PC_（61）BM/Al, where PEDOT：PSS and PC_（61）BM are used as hole and electron transport layers, respectively. The results show an improvement of hole charge transport as well as an increase of short-circuit current density and a reduction of series resistance, owing to the higher conductivity of the doped PEDOT：PSS. Consequently, it improves the whole performance of perovskite solar cell. The power conversion efficiency（PCE） of the device is improved from 8.57% to 11.03% under AM 1.5 G（100 mW/cm~2 illumination） after the buffer layer has been modified.