A simple fabrication of CH3NH3PbI3 perovskite for solar cells using low-purity PbI2 *

The CH 3 NH 3 PbI 3 (MAPbI 3 ) perovskite was usually prepared by high-purity PbI 2 with high cost. The low cost and low-purity PbI 2 was seldom reported for fabrication of MAPbI 3 because it cannot even dissolve well in widely adopted solvent of DMF. We developed an easy method to adapt low-purity PbI 2 for fabrication of high quality MAPbI 3 just by the simple addition of some hydrochloric acid into the mixture of low-purity PbI 2 , MAI and DMF. This straightforward method can not only help dissolve the low quality PbI 2 by reacting with some impurities in DMF, but also lead to a successful fabrication of high-quality perovskite solar cells with up to 14.80% efficiency comparable to the high quality PbI 2 precursors.