Lattice‐Defect‐Induced Piezo Response in Methylammonium‐Lead‐Iodide Perovskite Based Nanogenerator

Abstract

Methylammonium lead iodide (MAPbI3), a hybrid perovskite has become the semiconductor for case studies in several material properties due to its multi‐faceted electronic application. Other than photovoltaics, generation of piezoelectricity from hybrid perovskites has been reported previously, though its origin remained unsubstantiated. In this report, MAPbI3 with different degrees of crystal defects as determined by positron annihilation spectroscopy are developed through ball‐mill grinding procedure and utilized to fabricate flexible piezoelectric nanogenerators. We have demonstrated that at room temperature the lattice defects play the pivotal role in governing the ionic polarization which in principle governs the piezo‐effect in MAPbI3. The best device performance is exhibited by maximum defect containing sample having significant amount of Pb2+ defects. A device fabricated with 5 wt% PDMS composite produces piezo‐voltage of more than 100 V with a maximum power density of 0.3 mW/cm3 and can illuminate commercially available 30 blue light emitting diodes.

Defect induced room temperature ferromagnetism in methylammonium lead iodide perovskite

“…[24][25] The organic methylammonium (MA + ) cation and iodide (I -) anion, both contribute for defect formation, [24][25] but in some rare cases high energy lead (Pb 2+ ) vacancy can also form in the crystal lattice. 12 Thus, we observe that the lattice defects significantly influence the ionic polarization which in turn determines the magnitude of piezo-response in MAPbI 3 . 12 Of late, the defective nature of MAPbI 3 is also successfully utilized in fabricating non-volatile memory devices.…”

“…12 Thus, we observe that the lattice defects significantly influence the ionic polarization which in turn determines the magnitude of piezo-response in MAPbI 3 . 12 Of late, the defective nature of MAPbI 3 is also successfully utilized in fabricating non-volatile memory devices. 14,[26][27] Therefore, the recent findings distinctly corroborate the pivotal role played by the lattice defects in governing physical properties of organo lead halide perovskites.…”

“…The experimental evidence in support of the existence of defect driven magnetic moment for the polycrystalline MAPbI 3 sample having significant amount of point defects (V′ MA , V′′ Pb , V˙I) 12 was performed in SQUID covering all the three crystal phases namely, orthorhombic, tetragonal and cubic ranging from 100 K to 380 K. The nature of defects was previously determined by PAS for the polycrystalline samples prepared following the reported synthetic procedure. 12 1b reflects the gradually decreasing trend in magnetic moment with increasing temperature, but only by 25% even after reaching a temperature (380 K) which is well above the room temperature. This suggests that the origin of ferromagnetism in MAPbI 3 must be related with the lattice defects, because defect density progressively increases as the temperature is raised.…”

“…The rapid surge in the power conversion efficiency (PCE) of organic-inorganic hybrid lead halide perovskite based solar cell has generated huge excitement in the scientific community to achieve the maximum efficiency determined from the Shockley-Queisser calculations. [1][2][3] Exceptional photophysical [4][5][6] and charge transport properties [7][8][9] of organo lead halide perovskites have acted as a source of motivation, not only in exploring the field of photovoltaics, but to try for its multitude of applications in light emitting diodes (LEDs), 10 light emitting field effect transistors (LEFETs), 11 piezo-electric nanogenerators, [12][13] and non-volatile memory devices; 14 thus making hybrid perovskite as one of the highly followed research areas for material scientists in present days.…”

Recent advances in hybrid perovskite nanogenerators

“…73 The following PENGs based on MAPbI 3 -PDMS were optimized according to the MAPbI 3 crystal defect degrees which were determined by positron annihilation spectroscopy. 74 The lattice defects were reported to be very important to govern the ionic polarization in relation to the piezoeffect of MAPbI 3 . The PENGs at 5 wt% exhibited a high piezo-voltage of over 100 V with a maximum power density of 0.3 mW/cm 3 .…”