Efficient Perovskite Hybrid Solar Cells Through a Homogeneous High-Quality Organolead Iodide Layer

Fabricating homogeneous and high-quality perovskite thin films via low-temperature solution processing is a challenge to realizing high-efficiency perovskite hybrid solar cells (pero-HSCs). Here, an approach is reported to realize smooth surface morphology of methylammonium lead iodide (CH3NH3PbI3) perovskite thin films via using strong-polar ethanol solution rather than less-polar isopropanol solution, which was previously used as the solvent for preparing perovskite thin films. In comparison with the pero-HSCs processed from isopropanol solution, more than 40% enhanced efficiency is observed from pero-HSCs processed from ethanol solution. The enhanced efficiency is attributed to a homogeneous high-quality perovskite thin film with dramatically low root-mean-square roughness and completely conversion of lead (II) iodide (PbI2) to CH3NH3PbI3. The findings provide a simple way to realize high-efficiency high-reproducible pero-HSCs.