Identification and characterization of the intermediate phase in hybrid organic–inorganic MAPbI₃perovskite

Abstract

Perovskite films were prepared using single step solution deposition at different annealing temperatures and annealing times. The crystal structure, phases and grain size were investigated with XRD, XPS and SEM/EDX. The prepared films show a typical orientation of tetragonal perovskite phase and a gradual transition at room temperature from the yellow intermediate phase to the black perovskite phase. Films with high purity were obtained by sintering at 100 °C. In addition, the chemical composition and crystal structure of intermediate phase were investigated in detail. FTIR, UV-vis and NMR spectra revealed the occurance of DMF complexes. Interestingly, the intermediate phase could be transformed to the black perovskite phase upon X-ray irradiation. In addition, the recovery of the aged perovskite films from a yellow intermediate phase back to the black perovskite was shown to be viable via heating and X-ray irradiation.

Growth patterns and properties of aerosol-assisted chemical vapor deposition of CH3NH3PbI3 films in a single step

“…who identified the origin of these peaks from a monoclinic PbI2-MAI-DMF intermediate complex [15]. This implies that the complete formation of PVK films proceeds via an Scherrer's equation range between 31-36 nm.…”

Polarization‐Dependent Photoluminescence of a Highly (100)‐Oriented Perovskite Film

“…[5][6][7] As a result, the power-conversion efficiency (PCE) of the perovskite solar cells (PSC) has reached 25.2 %. [9,10] However, owing to a lack of deep-understanding of fabrication methods and the underlying mechanisms, a majority of perovskite thin films being reported are [001]-or randomly oriented ones, [11,12,22] leaving the perovskites oriented in [100] direction relatively less understood. [9,10] However, owing to a lack of deep-understanding of fabrication methods and the underlying mechanisms, a majority of perovskite thin films being reported are [001]-or randomly oriented ones, [11,12,22] leaving the perovskites oriented in [100] direction relatively less understood.…”

Antisolvent-assisted powder engineering for controlled growth of hybrid CH3NH3PbI3 perovskite thin films

“…The increase in the volume extent of the perovskite phase can be attributed to the X-ray-induced partial conversion of the powder into perovskite during the XRD measurements. 19 The similarity in the structures of the powder and the as-spun film indicates that the initial phase of the powder is retained in the film. After the annealing process, the two DMF-involving phases disappear while the PbI 2 and perovskite phases are observed.…”

“…The pattern of the gray powder mainly consists of peaks related to complexes of monoclinic PbI 2 -DMF 18-20 (green circles) and monoclinic PbI 2 -MAI-DMF 18,19 (black triangles). In addition, peaks related to tetragonal perovskite 18,19,21 (red diamonds) and the monoclinic MAPbI 3 -DMF 22 solvate (blue stars) can also be seen. The pattern of the corresponding as-spun film is similar to that of the powder; the only difference is that the intensity of the perovskite-related peaks is higher in the latter case.…”