Giant Bulk Photostriction and Accurate Photomechanical Actuation in Hybrid Perovskites

Abstract

It is well known that a material may be strained by mechanical, thermal, electric, magnetic, and light stimuli, and this effect has been extensively utilized in industries. However, the observed photostrictive effect usually occurs in the very thin surface layer and the photostriction of most bulk materials has been too small to be applied in a device until now. Here, a giant bulk photostriction is achieved, evidenced by the measured linear strain ε ≈ 0.72–0.43% for MAPbI3 single crystal plates of 0.05–0.5 mm in thickness under the 532 nm illumination. More importantly, the MAPbI3 single crystals also exhibit accurate photomechanical actuation functionality and the actuator can precisely adjust the displacement from hundreds of pm to tens of μm or the angle of a hard mirror from ≈10−6 to 0.2 degree. The present work not only unveils the huge bulk photostriction in lead halide perovskite single crystals but also demonstrates a wireless photomechanical actuator which is much simpler and smaller than conventional piezoelectric actuators.

Discovery of a 2D Hybrid Silver/Antimony‐Based Iodide Double Perovskite Photoferroelectric with Photostrictive Effect and Efficient X‐Ray Response

“…In other words, the vast majority of 980 nm laser energy is used to cause thermal expansion of (4,4‐DFPD) 4 AgSbI 8 . [ 58,60 ] As shown in Figure 7b, the Δ H caused by the same power of the 980 nm laser is much smaller than that of the 532 nm laser, which further confirms the photostrictive effect of (4,4‐DFPD) 4 AgSbI 8 . The photostriction (Δ L / L) is proportional to laser intensity (Figure 7c).…”

“…This value is larger than that of Ge (7.84 × 10 -8 %), GaAs (4 × 10 -5 %), CdS (7.5 × 10 -3 %), BiFeO 3 (0.003%), BaTiO 3 (0.04%) and MAPbI 3 (0.72%), but is smaller than that of SrRuO 3 and SrIrO 3 (2%). [60][61][62][63][64][65][66][67] To understand the origin of photostrictive effect of (4,4-DFPD) 4 AgSbI 8 , configurations after excitation of (4,4-DFPD) 4 AgSbI 8 are simulated using first-principles calculations (Figure 8a). It can be seen that (4,4-DFPD) 4 AgSbI 8 exhibits an archetypical dimensional perovskite structure, in which the octahedra are neatly arranged and connected with corner-sharing mode at the ground state.…”

“…This value is larger than that of Ge (7.84 × 10 –8 %), GaAs (4 × 10 –5 %), CdS (7.5 × 10 –3 %), BiFeO 3 (0.003%), BaTiO 3 (0.04%) and MAPbI 3 (0.72%), but is smaller than that of SrRuO 3 and SrIrO 3 (2%). [ 60–67 ]…”

Strain-Manipulated Photovoltaic and Photoelectric Effects of the MAPbBr3 Single Crystal

“…That is to say, the absolute value of d 33 increases with p increasing. The light with a higher p produces more electron–hole pairs, and thus, more photocarriers attend the charge and discharge process to increase the corresponding d 33 value. However, both J sc and d 33 are always zero when the 650 nm light illuminates either Au1 or Au2 and a periodic force is applied upon Au1/MAPbBr 3 /Au2 simultaneously.…”

“Forbidden” Polarisation and Extraordinary Piezoelectric Effect in Organometallic Lead Halide Perovskites

“…The jump in the displacement signal when the UV light is turned on and off, Figure 4b-d is caused by the photostrictive effect, already reported for MAPbX 3 . [56,57] Notably, the data reveal that the UV light polarizes samples. In the sample with graphite electrodes, Figure 4b, the pure electrostrictive response observed without UV light becomes partly piezoelectric under the light.…”