Chiral 2D Perovskites with a High Degree of Circularly Polarized Photoluminescence

Abstract

Chiral materials are of particular interest and have a wide range of potential applications in life science, material science, spintronic, and optoelectronic devices. Two-dimensional (2D) hybrid organic–inorganic lead halide perovskites have attracted increasing attention. Incorporating the chiral organic ligands into the layered lead iodide frameworks would introduce strong chirality in pure 2D perovskites for potential applications in circularly polarized light (CPL) emission and detection; nonetheless, studies on those aspects are still in their infancy. Here, we report on the strong CPL emission and sensitive CPL detection in the visible-wavelength range in pure chiral (R-/S-MBA)2PbI4 (MBA = C6H5C2H4NH3) 2D perovskites, which are successfully synthesized with a needle shape and millimeter size by incorporating the chiral molecules. The chiral 2D perovskites (R-MBA)2PbI4 and (S-MBA)2PbI4 exhibit an average degree of circularly polarized photoluminescence (PL) of 9.6% and 10.1% at 77 K, respectively, and a maximum degree of the circularly polarized PL of 17.6% is achieved in (S-MBA)2PbI4. The degree of circularly polarized PL dramatically decreases with increasing temperature, implying that the lattice distortion induced by the incorporated chiral molecules and/or temperature-dependent spin flipping might be the origin for the observed chirality. Finally, CPL detection has been achieved with decent performance in our chiral 2D perovskite microplate/MoS2 heterostructural devices. The high degree of the circularly polarized PL and excellent CPL detection together with the layered nature of pure chiral 2D perovskites enables them to be a class of very promising materials for developing and exploring spin associated electronic devices based on the chiral 2D perovskites.

Giant Optical Anisotropy of Perovskite Nanowire Array Films

“…In addition to 3D cubic perovskite we just mentioned, 2D perovskite is another perovskite family that possesses good polarization property because of its asymmetric layered crystal structure. For example, Ghoshal et al demonstrated a high DOLP of 0.73 from an individual (BA) 2 PbI 4 NW,43 and Ma et al reported polarized PL based on a group of chiral (MBA) 2 PbI 4 microplates with a DOLP of 0.176 44. Compared with perovskite‐based devices in the literature, the printed perovskite NW arrays in this study present the highest DOLP of 0.84, suggesting its potential for polarized light application.…”

Chiral Perovskites: Promising Materials toward Next‐Generation Optoelectronics

“…Compared with reduced‐dimensional perovskites, 2D perovskite films possess the merit of stronger chirality for the large mole fraction of organic chains, which exactly benefits for optoelectronic and spintronic devices. Very recently, needle‐shaped pure chiral ( R‐/S ‐MBA) 2 PbI 4 2D perovskites ( Figure a,b) have been reported to achieved a huge degree of the circularly polarized photoluminescence ( P value) of 17.6% (Figure c), which is much larger than that of RDCPs . In particular, with the increase of temperature, the chirality transfer reduces and the spin flip increases, resulting in the decrease of P value (Figure d).…”

“…c) Statistical histogram of the degree of circularly polarized PL |P| for ( R‐ and S‐ MBA) 2 PbI 4 excited by a 473 nm laser at 77 K. d) Degree of circularly polarized PL ( P ) as a function of temperature of two microplates for each type chiral 2D perovskites. Reproduced with permission . Copyright 2019, American Chemical Society.…”

“…[21,22] Since then, chiral perovskite materials have obtained increasing worldwide research attention and have been investigated on diverse properties. [23][24][25][26][27][28][29][30][31][32] Herein, a state-of-the-art overview of the progress made in the field of chiral perovskites has been summarized. We first briefly describe the common fabrication strategies of chiral perovskites.…”

Ultrathin Ruddlesden–Popper Perovskite Heterojunction for Sensitive Photodetection

“…In contrast to their 3D counterparts, the emerging 2D Ruddlesden–Popper perovskites have received increasing attention due to their better ambient stability . Up to now, 2D Ruddlesden–Popper perovskites have been demonstrated to exhibit abundant and adjustable optoelectronic properties, high quantum efficiency, and large specific surface area . Furthermore, the synthetic routes of layered perovskites which depend on self‐assemble with low cost and efforts are facial and economically .…”