Surface Modification of Cs0.1(CH3NH3)0.9PbI3 by Isopropanol as Green Antisolvent for Efficiency Enhancement of Perovskite Solar Cells

Surface modification of Cs-0.1(CH3NH3)(0.9)PbI3 is investigated by antisolvent-assisted crystallization (ASAC). The perovskite solar cells (PSCs) of FTO/SnO2/Cs-0.1(CH3NH3)(0.9)PbI3/spiro-OMeTAD/Ag are also fabricated. It is found that isopropanol-treated devices exhibit a power conversion efficiency (PCE) of 16.3%, which is higher than chlorobenzene- (11.5%) and toluene-treated devices (12.8%). The efficiency enhancement by isopropanol treatment can be attributed to better surface coverage, larger grain size, and less pinholes confirmed by scanning electron microscopy (SEM) and X-rays diffraction (XRD) results, indicating an increase in short-circuit current density (J(sc)). In addition, the increase in open-circuit voltage (V-oc) can be confirmed by photoluminescence (PL) spectra, which can be suggested to the reduce the nonradiative recombination loss in the isopropanol-treated film. The wettability of perovskite films is studied by contact angle measurement, resulting in a higher hydrophobic surface from isopropanol-treated devices. Also, the charge dynamic behavior of PSC devices is investigated by open-circuit voltage decay (OCVD) measurement. It is found that the charge carrier lifetime of the isopropanol-treated device is longer than that of chlorobenzene and toluene. Therefore, surface modification of perovskite by isopropanol treatment can enhance efficiency and isopropanol can be used as an alternative green antisolvent for the perovskite process.

Automated summary

The surface modification of Cs-0.1(CH3NH3)(0.9)PbI3 using isopropanol treatment leads to improved efficiency in perovskite solar cells due to better surface coverage, larger grain size, and less pinholes. Additionally, isopropanol treatment results in a more hydrophobic surface and longer charge carrier lifetime, contributing to enhanced performance of the devices.