A two-layer structured PbI₂thin film for efficient planar perovskite solar cells

Abstract

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.

Ultrahigh Responsivity and Detectivity Graphene–Perovskite Hybrid Phototransistors by Sequential Vapor Deposition

“…The peaks located at 2 θ  = 14.29°, 28.55°, 32°, 40.73°, and 43.27° correspond to the (110), (220), (310), (224), and (314) planes of MAPbI 3 perovskite. The (110) and (220) preferred orientations were observed, which is consistent with the reported results for MAPbI 3 perovskite films46 and confirms that the compact crystalline MAPbI 3 perovskite films were achieved by sequential vapor deposition. The stoichiometry of MAPbI 3 perovskite was obtained by X-ray photoemission spectroscopy (XPS) using Mg K α radiation ( hν  = 1253.6 eV).…”

Fiber-Shaped Perovskite Solar Cells with High Power Conversion Efficiency

“…For the PbI 2 crystal, the peaks at 12.6°, 25.5°, 38.5°, and 52.2° correspond to the (006), (0012), (0018), and (0024) planes, respectively. For the perovskite CH 3 NH 3 PbI 3 material, the peaks at 14.08°, 28.41°, 31.85°, and 43.19° correspond to the (110), (220), (310), and (314) planes, respectively . For the perovskite layer derived from a dense and compact PbI 2 layer, the peaks that correspond to PbI 2 could be clearly observed at the angle of 12.6° with a similar intensity to 14.08° that corresponded to CH 3 NH 3 PbI 3 .…”

Effect of the Ultrasonic Substrate Vibration on Nucleation and Crystallization of PbI2 Crystals and Thin Films

“…Small and compact PbI 2 crystallites preferentially developed along the (001) plane can provide low electrical resistivity and large band gap, suitable for sensor development [5,9], and the layered and planar PbI 2 is suitable for the development of flexible detectors [10]. In addition, PbI 2 is a major precursor for the fabrication of methylammonium lead perovskite solar cells [11], using a two-step deposition method, in which a PbI 2 thin film is deposited first, which serves as a template for the deposition of the second precursor [6,8,12,13]. deposition method, in which a PbI2 thin film is deposited first, which serves as a template for the deposition of the second precursor [6,8,12,13].…”

“…In addition, PbI 2 is a major precursor for the fabrication of methylammonium lead perovskite solar cells [11], using a two-step deposition method, in which a PbI 2 thin film is deposited first, which serves as a template for the deposition of the second precursor [6,8,12,13]. deposition method, in which a PbI2 thin film is deposited first, which serves as a template for the deposition of the second precursor [6,8,12,13].…”

“…The functional properties of the crystalline substances, such as their band gap, electrical and thermal conductivity, transparency, and chemical and thermal stability are not only dependent of the chemical composition and the basic crystal structure, but also depend on the characteristics of their crystallites, such as size and size distribution, preferential orientation, alignment, and number density [1][2][3][4][5][6][7][8]. This work focuses on the nucleation and crystallization of lead iodide (PbI 2 ), a semiconductor with numerous applications.…”