Search

2D chiral perovskite has greatly boosted the development of optoelectronic devices, ranging from nonlinear optics, spintronics, and ferroelectrics to energy harvesting devices. Despite circularly polarized light (CPL) detection based on chiral perovskite has been achieved, the environmental humidity‐, ultraviolet (UV), and temperature‐induced structural degradation and its large electro‐phonon coupling restrict its commercial application. Here, this study first realizes polymerized chiral perovskite single‐crystal films by combining in situ cross‐linking polymerization with the space‐confined crystallization method. Compared with uncross‐linked chiral perovskites, cross‐linked chiral perovskites exhibit enhanced crystallinity and lattice rigidity, yielding high‐performance circularly polarized photodetectors with a maximum anisotropy factor of 0.22, the responsivity of 1.6 A W−1, and detectivity of 2.17 × 1013 Jones. In addition, flexible circularly polarized photodetectors with extremely high mechanical stability are also realized originating from the polymer‐like behavior of cross‐linked chiral perovskite single‐crystal films. This study opens up new avenues to further enhance the performance and stability of portable and wearable devices based on chiral perovskites. [ABSTRACT FROM AUTHOR]

Highlights: Multidimensional detection of intensity, wavelength, polarization, and angle of the incidence light significantly accelerates the development of optical information technology and artificial intelligence fields. The first comprehensive overview of the advancement of multifunctional photodetectors for perovskite semiconductors ranging from polarized light detection, spectral detection, and angle-sensing detection to self-powered detection is summarized. The existing problems and perspectives are discussed which can inspire more researchers to rationally design new perovskite materials and micro/nano-structure for high-performance multifunctional photodetectors. Multifunctional photodetectors boost the development of traditional optical communication technology and emerging artificial intelligence fields, such as robotics and autonomous driving. However, the current implementation of multifunctional detectors is based on the physical combination of optical lenses, gratings, and multiple photodetectors, the large size and its complex structure hinder the miniaturization, lightweight, and integration of devices. In contrast, perovskite materials have achieved remarkable progress in the field of multifunctional photodetectors due to their diverse crystal structures, simple morphology manipulation, and excellent optoelectronic properties. In this review, we first overview the crystal structures and morphology manipulation techniques of perovskite materials and then summarize the working mechanism and performance parameters of multifunctional photodetectors. Furthermore, the fabrication strategies of multifunctional perovskite photodetectors and their advancements are highlighted, including polarized light detection, spectral detection, angle-sensing detection, and self-powered detection. Finally, the existing problems of multifunctional detectors and the perspectives of their future development are presented. [ABSTRACT FROM AUTHOR]

Color‐cognitive detection plays an important role in many developing applications such as optical sensing, high‐solution imaging, wearable biometric monitoring, and human visual cognitive system. Although color‐cognitive devices have been demonstrated, the large size, complex manufacturing, high cost, and non‐flexible processing impede their applications for distinguishing color information. Herein, gradient bandgap‐tunable perovskite microwire arrays with excellent crystallinity and pure crystallographic orientation are realized by the synergy of the capillary‐bridge assembly method and mild component engineering processing, yielding high‐performance integrated color‐cognitive devices with the spectral resolution of 14 nm ranging from 405 nm to 760 nm, responsivities over 103 A W−1, and detectivities over 1015 Jones. Furthermore, the integrated flexible color‐cognitive devices are demonstrated for accurately recognizing similar colors, which can be applied in color blindness correction. The efficient color recognition performances, together with the flexible processing, open new opportunities for the on‐chip integration of wearable devices based on microwire arrays. [ABSTRACT FROM AUTHOR]

The realization of polarized photodetection vigorously accelerates the development of applications in quantum communication, medicine, imaging, and sensing. Polarized light detection has been realized based on chiral perovskites, but the high concentrations of toxic lead and instability in those reported perovskites impose difficulties for their commercial applications. Furthermore, the precise patterning of perovskite arrays with high crystallinity is in high demand for the integration of optoelectronic devices. Herein, pure (001)‐orientated lead‐free chiral 2D double perovskite single‐crystalline microwire arrays are fabricated by the capillary‐bridge confined assembly technique. Perovskite microwire arrays present remarkable environmental stability under ambient conditions. With the synergy of the excellent crystallinity and sensitive circular‐polarization absorption of chiral perovskite microwire arrays, outstanding circularly polarized light photodetectors are realized, with responsivity exceeding 52 mA W−1 and detectivity exceeding 3.9 × 1011 Jones. [ABSTRACT FROM AUTHOR]

State‐of‐the‐art optoelectronic devices based on metal‐halide perovskites demand solution‐processed structures with high crystallinity, controlled crystallographic orientation, and enhanced environmental stability. Formamidinium lead iodide (α‐FAPbI3) possesses a suitable bandgap of 1.48 eV and enhanced thermal stability, whereas perovskite‐type polymorph (α‐phase) is thermodynamically instable at ambient temperatures. Stable α‐FAPbI3 perovskite 1D structure arrays with high crystallinity and ordered crystallographic orientation are developed by controlled nucleation and growth in capillary bridges. By surface functionalization with phenylethylammonium ions (PEA+), FAPbI3 wires sustain a stable α‐phase after 28 day storage in the ambient environment with a relative humidity of 50%. Enhanced photoluminescence (PL) intensity and elongated PL lifetime demonstrate suppressed trap density and high crystallinity in these 1D structures, which is also reflected by the enhanced diffraction density and pure (001) crystallographic orientation in the grazing‐incidence wide‐angle X‐ray scattering (GIWAXS) pattern. Based on these high‐quality 1D structures, sensitive photodetectors are achieved with average responsivities of 5282 A W−1, average specific detectivities of more than 1.45 × 1014 Jones, and a fast response speed with a 3 dB bandwidth of 15 kHz. [ABSTRACT FROM AUTHOR]

All‐inorganic metal‐halide perovskites CsPbX3 (X = Cl, Br, I) exhibit higher stability than their organic–inorganic hybrid counterparts, but the thermodynamically instable perovskite α phase at room temperature of CsPbI3 restricts the practical optoelectronic applications. Although the stabilization of α‐CsPbI3 polycrystalline thin films is extensively studied, the creation of highly crystalline micro/nanostructures of α‐CsPbI3 with large grain size and suppressed grain boundary remains challenging, which impedes the implementations of α‐CsPbI3 for lateral devices, such as photoconductor‐type photodetectors. In this work, stable α‐CsPbI3 perovskite nanowire arrays are demonstrated with large grain size, high crystallinity, regulated alignment, and position by controlling the dewetting dynamics of precursor solution on an asymmetric‐wettability topographical template. The correlation between the higher photoluminescence (PL) intensity and longer PL lifetime indicates the nanowires exhibit stable α phase and suppressed trap density. The preferential (100) orientation is characterized by discrete diffraction spots in grazing incidence wide‐angle scattering patterns, suggesting the long‐range crystallographic order of these nanowires. Based on these high‐quality nanowire arrays, highly sensitive photodetectors are realized with a responsivity of 1294 A W−1 and long‐term stability with 90% performance retention after 30‐day ambient storage. Stable α‐CsPbI3 nanowire arrays with high crystallinity, large grain size, and preferential crystallographic orientation are demonstrated on an asymmetric‐wettability topographical template. The suppressed grain boundary and surface trap of these nanowires are reflected by longer photoluminescence lifetime and long‐range crystallographic alignment. These high‐quality nanowires exhibit highly sensitive photodetection with responsivity of 1294 A W−1 and long‐term stability. [ABSTRACT FROM AUTHOR]