A two-layer structured PbI2 thin film for efficient planar perovskite solar cells

作者：Ying, Chao; Shi, Chengwu^*; Wu, Ni; Zhang, Jincheng; Wang, Mao

来源：Nanoscale, 2015, 7(28): 12092-12095.

DOI：10.1039/c5nr03511b

• Charge recombinations
• Charge separations
• Coating procedures
• Hole migration
• Perovskite thin films
• Photo-electric conversion efficiency
• Short-circuit photocurrent densities
• Vacuum thermal evaporation

In this paper, a two-layer structured PbI2 thin film was constructed by the spin-coating procedure using a 0.80 M PbI2 solution in DMF and subsequent close-spaced vacuum thermal evaporation using PbI2 powder as a source. The bottom PbI2 thin film was compact with a sheet-like appearance, parallel to the FTO substrate, and can be easily converted to a compact perovskite thin film to suppress the charge recombination of the electrons of the TiO2 conduction band and the holes of the spiro-OMeTAD valence band. The top PbI2 thin film was porous with nano-sheet arrays, perpendicular to the FTO substrate, and can be easily converted to a porous perovskite thin film to improve the hole migration from the perovskite to spiro-OMeTAD and the charge separation at the perovskite/spiro-OMeTAD interface. The planar perovskite solar cells based on the two-layer structured PbI2 thin film exhibited a photoelectric conversion efficiency of 11.64%, along with an open-circuit voltage of 0.90 V, a short-circuit photocurrent density of 19.29 mA cm(-2) and a fill factor of 0.67.

• 出版日期2015
• 单位合肥工业大学