While most work carried out to date has focused on the solvent annealing of perovskite, in the present work, we focused on the solvent annealing of lead iodide. Based on the two-step spin-coating method, we designed a screening method to search for an effective solvent annealing process for PbI2. PbI2 films were annealed in diverse solvent atmospheres, including DMF, DMSO, acetone, and isopropanol (IPA). We found that the solvent annealing of PbI2 in the DMF, acetone, and IPA atmospheres resulted in dense PbI2 films, which impeded the complete conversion of PbI2 to CH3NH3PbI3. Surprisingly, employing the DMSO solvent annealing process for PbI2 led to porous PbI2, which facilitated the complete conversion of PbI2 to perovskite with larger grain sizes. Solar cells fabricated using the DMSO solvent annealing process exhibited the best efficiency of 18.5%, with a fill factor of 76.5%. This unique solvent annealing method presents a new way of controlling the perovskite film quality for highly efficient solar cells.
|Number of pages||8|
|State||Published - Dec 21 2016|
Bibliographical noteFunding Information:
This work was supported by the National Natural Science Foundation of China under Grant No. 61474016 and 61405026, 61371046, 61421002, 6157031208, 61471085, and National Higher-education Institution General Research and Development Fund (ZYGX2014J044), Projects of International Cooperation of Sichuan Province (no. 2014HH0041). This work was also partially supported by the University of Kentucky and Advanced Semiconductor Processing Technology, LLC.
© 2016 The Royal Society of Chemistry.
ASJC Scopus subject areas
- Materials Science (all)