Investigation of Structural and Electronic Properties of CH3NH3PbI3 Stabilized by Varying Concentrations of Poly(Methyl Methacrylate) (PMMA)

Abstract

Abstract:Studies have shown that perovskites have a high potential of outdoing silicon based solar cells in terms of solar energy conversion, but their rate of degradation is also high. This study reports on improvement on the stability of CH 3 NH 3 PbI 3 by passivating it with polymethylmethacrylate (PMMA). Structural and electronic properties of CH 3 NH 3 PbI 3 stabilized by polymethylmethacrylate (PMMA) were investigated by varying concentrations of PMMA in the polymer solutions. Stability tests were performed over a period of time using modulated surface photovoltage (SPV) spectroscopy, X-ray diffraction (XRD), and photoluminescence (PL) measurements. The XRD patterns confirm the tetragonal structure of the deposited CH 3 NH 3 PbI 3 for every concentration of PMMA. Furthermore, CH 3 NH 3 PbI 3 coated with 40 mg/mL of PMMA did not show any impurity phase even after storage in air for 43 days. The Tauc gap (E Tauc ) determined on the basis of the in-phase SPV spectra was found in the range from 1.585 to 1.62 eV for the samples stored during initial days, but shifted towards lower energies as the storage time increased. This can be proposed to be due to different chemical reactions between CH 3 NH 3 PbI 3 /PMMA interfaces and air. PL intensity increased with increasing concentration of PMMA except for the perovskite coated with 40 mg/mL of PMMA. PL quenching in the perovskite coated with 40 mg/mL of PMMA can be interpreted as fast electron transfer towards the substrate in the sample. This study shows that, with an optimum concentration of PMMA coating on CH 3 NH 3 PbI 3 , the lifetime and hence stability on electrical and structural behavior of CH 3 NH 3 PbI 3 is improved.

Surface Photovoltage Spectroscopy Study of Ultrasonically Sprayed‐Aerosol CH3NH3PbI3 Perovskite Crystals

“…For example, an E t of 38 meV was found for the CH 3 NH 3 PbI 3 perovskite deposited on a layer of the TiO 2 whereas the value of 21 meV was reported for a double layer design by having TiO 2 with the organic fullerene derivatives . Awino et al showed the dependence of PMMA concentrations for stabilizing the CH 3 NH 3 PbI 3 . The values of E t were found to be in a range of 17–45 meV and were strongly dependent on the concentrations of PMMA being used.…”

Crystallization Retardation and Synergistic Trap Passivation in Perovskite Solar Cells Incorporated with Magnesium-Decorated Graphene Quantum Dots

“…The diffraction peaks at 14.07, 20.18, 22.4, 24.45, 26.23, 31.6, 35.8, 43.12, and 49.8° are indexed to (110), (112), (121), (211), (220), (330), (132), (314), and (404) planes, which are characteristic of the tetragonal phase of MAPbI 3 . 36 , 68 Regarding the XRD of perovskite/GQD and perovskite/MGQD samples, the patterns show no diffraction peaks corresponding to GQD and MGQD owing to the small decoration. Moreover, the fwhm of the XRD pattern, especially the one centered at 26.23°, decreased in the order of pristine perovskite > perovskite/GQD > perovskite/MGQD, and based on the Scherrer equation, these changes demonstrated the modification in grain size and crystalline structure of perovskite film when it was incorporated with GQD and MGQD ( Figure 6 c).…”

“…67 To evaluate the effect of GQD and MGQD incorporation on the crystalline structure of the perovskite layer, XRD analysis was carried out on pristine perovskite, perovskite/GQD, and perovskite/MGQD samples, as shown in Figure 6a−c 132), (314), and (404) planes, which are characteristic of the tetragonal phase of MAPbI 3 . 36,68 Regarding the XRD of perovskite/GQD and perovskite/ MGQD samples, the patterns show no diffraction peaks corresponding to GQD and MGQD owing to the small decoration. Moreover, the fwhm of the XRD pattern, especially the one centered at 26.23°, decreased in the order of pristine perovskite > perovskite/GQD > perovskite/MGQD, and based on the Scherrer equation, these changes demonstrated the modification in grain size and crystalline structure of perovskite film when it was incorporated with GQD and MGQD (Figure 6c).…”

Growth of Hybrid Perovskite Films via Single‐Source Perovskite Nanoparticle Evaporation

“…In order to address the above‐mentioned limitations of vacuum‐based methods, flash evaporation and single‐source thermal evaporation methods are potentially being studied [2a,12,20] . However, low stability of hybrid perovskite films against atmospheric agents remains a challenge [21] which is addressed by various groups using various additives during film fabrication [22] or post deposition coating of perovskite films with a thin polymer layer [23] . Therefore, a simple and efficient vacuum‐based method is required to get phase pure perovskite thin films; where one can avoid the use of MAX and post‐deposition treatments to the thin film.…”

“…[2a,12,20] However, low stability of hybrid perovskite films against atmospheric agents remains a challenge [21] which is addressed by various groups using various additives during film fabrication [22] or post deposition coating of perovskite films with a thin polymer layer. [23] Therefore, a simple and efficient vacuum-based method is required to get phase pure perovskite thin films; where one can avoid the use of MAX and postdeposition treatments to the thin film. Herein, we demonstrate, a simple, facile and efficient vacuum-based method to fabricate perovskite thin films.…”