Unveiling Predominant Air-Stable Organotin Bromide Perovskite toward Mechanical Energy Harvesting

Abstract

Organotin halide perovskites are developed as an appropriate substitute to replace highly toxic lead-based hybrid perovskites, which are a major concern for the environment as well as for human health. However, instability of the lead-free Sn-based perovskites under ambient conditions has hindered their wider utility in device applications. In this study, we report a predominantly stable lead-free methylammonium tin bromide (MASnBr 3 ) perovskite that has air stability over 120 days without passivation under ambient conditions. Further, the feasibility of this predominant air-stable MASnBr 3 perovskite for use in the harvesting of mechanical energy is described with the fabrication of an ecofriendly, flexible, and cost-effective piezoelectric generator (PEG) using MASnBr 3 −polydimethylsiloxane composite films. The fabricated PEG exhibits high performance along with good mechanical durability and long-term stability. This flexible device reveals a high piezoelectric output voltage of ∼18.8 V, current density of ∼13.76 μA/cm 2 , and power density of ∼74.52 μW/cm 2 under a periodic applied pressure of 0.5 MPa. Further, the ability of PEG to scavenge energy from various easily accessible biomechanical movements is demonstrated. The energy generated from PEG by finger tapping is stored in a capacitor and is used to power both a stopwatch and a commercial lightemitting diode. These findings offer a new insight to achieve long-term air-stable Sn-based hybrid perovskites, demonstrating the feasibility of using organotin halide perovskites to realize highly efficient, ecofriendly, mechanical energy harvesters with a wide range of utility that includes wearable and portable electronics as well as biomedical devices.

Achieving Ultrahigh Piezoelectricity in Organic–Inorganic Vacancy-Ordered Halide Double Perovskites for Mechanical Energy Harvesting

“…26 Subsequently, a series of perovskites, including MASnBr3, FAPbBr2I and Cl/Br-MAPbI3, have been developed for efficient 20 PNGs via the piezoelectric composite films. [27][28][29][30][31] However, the aforementioned OIHPs evolved from the shadows of the SCs possess limited piezoelectric coefficients. Therefore, extensive efforts 22 have been devoted to searching for highly piezoelectric OIHPs.…”

Recent advances in hybrid perovskite nanogenerators

“…D, Schematic representation of eco‐friendly MASnBr 3 ‐PDMS PENGs. Reproduced with permission: Copyright 2020, American Chemical Society 75 . E, Schematic representation presenting the flexible device structure of FAPbBr 3 ‐polyvinylidene difluoride (PVDF) PENGs.…”

“…Eco‐friendly PENGs were also fabricated using lead‐free MASnBr 3 powders with a high piezoelectric output voltage of ∼18.8 V and current density of ∼13.76 μA/cm 2 under a periodically applied pressure of 0.5 MPa (Figure 3D). 75 The instability of Sn‐based perovskites under ambient conditions was overcome by enwrapping in PDMS which led to long device stability over 120 days.…”

ASnX3—Better than Pb‐based Perovskite

“…Further, it shows high mechanical durability and air stability over 120 days. [ 146 ] Ippili et al. also reported a MASnI 3 /PVDF‐based PENG formed by the antisolvent‐assisted collision technique (ACT) under ambient air conditions.…”