Sputtered PbI₂ with Post‐Processing for Perovskite Solar Cells

Abstract

Conformal deposition of perovskite films on textured silicon surfaces using a dry process is crucial for producing high‐performance perovskite/silicon tandem solar cells. Herein, a radio frequency magnetron sputtering process is used with a PbI2 target to deposit precursor films. Iodination, thermal annealing, and dimethyl sulfoxide treatment are employed as posttreatment processes to improve the stoichiometry, crystallinity, and surface morphology of the PbI2 precursor. The precursor films are converted into perovskite using direct contact conversion process, and the interfacial and bulk properties are enhanced by methylamine vapor annealing to fabricate perovskite solar cells with a power conversion efficiency of 12.2%. Also, 18.3% efficiency is confirmed at a wider voltage sweep range, which suggests that further efficiency improvement is possible by removing defects inside the perovskite. Finally, uniform perovskite films are conformally deposited on a 25 cm2 textured silicon surface. With such high‐efficiency potential and conformality, the method of sputtering PbI2 can open a new way to fabricate perovskite/silicon tandem solar cells.

Optoelectronic properties of perovskite thin films derived from lead sulfide via radio frequency magnetron sputtering: effect of the substrate temperature

“…These indexes were in good agreement with the literature and theoretically calculated values with tetragonal phases of MAPbI 3 . 12,17,26) The patterns also revealed that the (110) peak became broader with lower intensities, which could result from lattice-distortion of MAPbI 3 from the transformation to fibrous interconnected grain.…”

“…[5][6][7][8][9] Among the fabrication processes, RF sputtering provides outstanding advantages in terms of precise film formation, high uniformity, and structural control. [10][11][12] In addition, the crystal structure of sputtered films could be controlled according to the Thornton structural zone model, which determines the grain size, orientation, and morphology of sputtered films as a function of the given specific pressure and substrate temperature. [13][14][15] This level of control is critical for tailoring the optical, electrical, and functional properties of the film for various device applications.…”