Chemical Vapor Deposited Mixed Metal Halide Perovskite Thin Films

Abstract

In this article, we used a two-step chemical vapor deposition (CVD) method to synthesize methylammonium lead-tin triiodide perovskite films, MAPb1−xSnxI3, with x varying from 0 to 1. We successfully controlled the concentration of Sn in the perovskite films and used Rutherford backscattering spectroscopy (RBS) to quantify the composition of the precursor films for conversion into perovskite films. According to the RBS results, increasing the SnCl2 source amount in the reaction chamber translate into an increase in Sn concentration in the films. The crystal structure and the optical properties of perovskite films were examined by X-ray diffraction (XRD) and UV-Vis spectrometry. All the perovskite films depicted similar XRD patterns corresponding to a tetragonal structure with I4cm space group despite the precursor films having different crystal structures. The increasing concentration of Sn in the perovskite films linearly decreased the unit volume from about 988.4 Å3 for MAPbI3 to about 983.3 Å3 for MAPb0.39Sn0.61I3, which consequently influenced the optical properties of the films manifested by the decrease in energy bandgap (Eg) and an increase in the disorder in the band gap. The SEM micrographs depicted improvements in the grain size (0.3–1 µm) and surface coverage of the perovskite films compared with the precursor films.

Efficient Metal‐Halide Perovskite Photovoltaic Cells Deposited via Vapor Transport Deposition

“…In addition, RBS can detect both heavy and light elements, which might offer a handle at also probing nitrogen or carbon content in MHP materials. [51][52][53] The samples used for RBS were first characterized by XRD, with results shown in Figure 5a. From the peak at 2θ = 12.6˚in XRD, one film is stoichiometric MAPbI 3 (%250 nm on SnO 2 :TiO x / ITO) and the other is MAPbI 3 with PbI 2 excess (%600 nm on SnO 2 :TiO x /ITO).…”

Film Fabrication of Perovskites and their Derivatives for Photovoltaic Applications via Chemical Vapor Deposition

“…In addition to combining with spin coating or thermal evaporation, LPCVD could be utilized to prepare perovskite films solely through sequential deposition in one reactor. − As a result, the whole deposition process could be simplified further. MAPbI 3 films with a large grain size of around 3.8 μm were obtained through two-step LPCVD, and the morphology of the final perovskite film was determined by the LPCVD-PbI 2 film .…”

“…MAPbI 3 films with a large grain size of around 3.8 μm were obtained through two-step LPCVD, and the morphology of the final perovskite film was determined by the LPCVD-PbI 2 film . Using more complex precursors or adding more CVD steps, perovskite films with mixed metals or halides could be fabricated as well, such as Sn-doped and Cl-doped MAPbI 3 . , It is worth noting that the thin films of lead-free materials, Cs 2 SnI 6 and MA 3 Bi 2 I 9 , were successfully synthesized by sequential LPCVD. − …”

Blade Coating High‐Quality Formamidinium–Cesium Lead Halide Perovskites with Green Solvent for Efficient and Stable Solar Cells

“…Therefore, another important task for further developing PVSK solar cells is to transfer the high PCE from small‐area devices to large‐area modules. Scalable coating methods for PVSK under study include blade coating, [ 6 ] spray coating, [ 7 ] slot die coating, [ 8 ] chemical vapor deposition, [ 9 ] etc. Among all technologies, heat‐assisted blade coating is widely used in laboratory research because of its simplicity of equipment, adjustability of precursor, and continuity of film formation [6c,d,10] .…”