Chlorine-substituted chiral 2D perovskite microwires with enhanced lattice rigidity for sensitive circularly polarized light detection

Chiral two-dimensional(2D) perovskites offer numerous attractive features for optoelectronics owing to their soft, deformable lattices and a high degree of chemical tunability. While tremendous advances have been made in perovskite-based direct circularly polarized light(CPL) detection, the low circular polarization anisotropy factor and sensitivity of those photodetectors arising from large lattice distortion still limit practical applications. Herein, chiral 2D perovskite-based single-crystalline microwire arrays with enhanced circular dichroism(CD) absorption are fabricated with the synergy of the capillary-bridgeconfined assembly method and chlorine-substituted phenethylamine(Cl-MBA). Compared with phenethylamine(MBA)-inserted perovskites, the smaller lattice distortion and increased halogen–halogen interaction within Cl–MBA-inserted perovskites strengthen lattice rigidity and weaken electron–phonon coupling to improve carrier transport and thermal stability, resulting in high-performance CPL photodetectors with an anisotropy factor of 0.25, responsivity exceeding 95.7±9.3 A W^(-1)and detectivity exceeding(3.05±0.30)×10^(13)Jones. This work opens a new perspective to modulate circular polarization sensitivity and will be helpful to realize promising implementations in quantum computation and communication.

Optical and electrical modulation in ultraviolet photodetectors based on organic one-dimensional photochromic arrays

Organic photochromic materials have drawn considerable attention for their potential applications in large-scale and low-cost optoelectronics owing to unique tunable physicochemical properties.For organic photodetectors,photochromic materials have realized optical and electrical engineering of semiconductor layers,which incorporate not only tunable performance,but also functionalities to optoelectronic devices.However,the essential challenge is to assemble large-area photochromic micro-and nanostructure arrays with controllable geometry and precise alignment,which restricts the integration of multifunctional optoelectronic devices.Herein,we fabricate organic photochromic one-dimensional(1D)arrays via a feasible solution process through the confined crystallization of organic molecules.By modulating and controlling the photoisomerization behaviors,these 1D photochromic arrays possess broad spectral tunability,which ensure tunable photoresponse.Furthermore,we investigate the crystallographic transition and electronic performance variation of these 1D photochromic arrays.By adjusting the dwell time of ultraviolet(UV)irradiation,the UV photochromic photodetectors realize tunable and repeatable responsivity from 85.6 to 0.709 mA/W.Our work provides new possibilities for optical and electrical engineering of photochromic microwires towards the integration of multifunctional optoelectronic devices.

Reversible phase transition for switchable second harmonic generation in 2D perovskite microwires

Highly efficient second-harmonic generation(SHG)has facilitated the development of nanophotonics and sustained promising applications,ranging from electro-optical modulation,frequency conversion,and optical frequency combs to pulse characterization.Although controllable SHG switching has been observed in nanophotonics structures and molecule systems,the relatively small SHG switching contrast impedes its application in switchable nonlinear optics.Herein,reversible phase transitions between glassy and crystalline states without material degradation are demonstrated based on solution-processed chiral perovskite microwire arrays.Breaking of lattice inversion symmetry and high crystallinity support efficient SHG in microwire arrays.By synergy of high-performance SHG and reversible phase transitions between glassy and crystalline states,reversible switching of SHG is demonstrated under facile conditions.The high SHG switching performances,together with a small footprint,pave the way toward the integration of switchable nonlinear devices based on microwire arrays.