Chiral 1D Hybrid Metal Halides with Piezoelectric Energy Harvesting and Sensing Properties

Abstract

Chiral hybrid metal halides have been widely studied in the field of photondetectors, chiral optics, and spintronics due to their great structural flexibility and suitable bandgaps. Inspired by such great progress made in the abovementioned fields, continuous efforts need to be paid to seek other interesting applications for chiral hybrid metal halides. Herein, the synthesis of a pair of one‐dimensional enantiomorphic hybrid metal halide piezoelectrics, R/SMPCdCl4(R/SMP = R/S‐2‐methylpiperazine), and their applications in piezoelectric energy harvesting and sensing are reported. Density functional theory calculations show that these chiral piezoeletrics possess low elastic properties and high piezoelectric constants (16.71, 8.39, and 7.35 pC N−1). In addition, devices made of RMPCdCl4/PDMS (PDMS = polydimethylsiloxane) composite films are fabricated for piezoelectric energy harvesting and sensing. The piezoelectric energy harvesters with optimized content of 15 wt% RMPCdCl4/PDMS show not only excellent performance with an open‐circuit voltage of 2.57 V, short‐circuit current of 0.37 μA, and power density of 0.55 μW cm−2 but also outstanding stability of more than 3500 cycles. Meanwhile, these piezoelectric energy harvesters exhibit prominent sensing properties for detecting tapping, finger bending, walking, and running. It is demonstrated that chiral hybrid metal halides hold great potential in intelligent wearable and sensing devices.

A homochiral polar molecular piezoelectric material with phase transition and high piezoelectricity precisely designed by cyanomethyl group substitution

“…The longitudinal piezoelectric coefficient of [DCM-( S )-MPP][ClO 4 ] was compared to other piezoelectric materials as shown in Fig. 4b, which exceeds the value of many classical homo-chiral compounds, including the Rochelle salt (7 pC/N), 9 [ R - and S -1-(4-chlorophenyl)ethylammonium] 2 PbI 4 ( R - and S -LIPF) (3 pC/N), 41 [HDABCO(1,4-diazabicyclo[2.2.2]octonium)][ l -MA (malic acid)] (4 pC/N), 42 [HDABCO(1,4-diazabicyclo[2.2.2]octonium)][ d -MA (malic acid)] (5 pC/N), 42 [4-(phenyldiazenyl)anilinium] l -tartrate (7 pC/N), 29 RMPCdCl 4 (RMP = R -2-methylpiperazine) (8.39 pC/N), 43 close to imidazolium l -camphorsulfonate (19 pC/N). 44 For the polar ionic crystal of [DCM-( S )-MPP][ClO 4 ], the spontaneous polarization mainly originates from the deviation of positive/negative charge centers.…”

Piezoelectric Charge Coefficient of Halide Perovskites

“…These materials showed a bandgap of ~2.3 eV and good absorption in the visible spectral range [46]. Using DFT calculations, a one-dimensional enantiomorphic hybrid metal halide R/SMPCdCl 4 (R/SMP = R/S-2-methylpiperazine) with chiral properties was predicted to have high piezoelectric constants (16.71, 8.39, and 7.35 pC/N) [47]. By introducing chiral and rigid organic cations of α-phenylethylammonium, R-α-PEA + , and S-α-PEA + into bismuth-based hybrid halides, chiral (R-α-PEA) 4 Bi 2 I 10 and (S-α-PEA) 4 Bi 2 I 10 crystals (centimetre-sized single crystals) were formed to yield an enhanced piezoelectric coefficient d 22 of 32 pC/N, as measured using the quasi-static method [48].…”