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Halide double perovskites have emerged as remarkable semiconductors owing to their nontoxicity and superior optoelectronic features. Despite recent exciting progress, halide double perovskites with...

Single crystals of lead halide hybrid perovskites (e. g., CH3NH3PbI3 and CsPbBr3) have been developed as promising candidates for X-ray detection, owing to their excellent attributes including low ...

Bismuth-based hybrid perovskites have recently attracted great attention for their environmentally friendly processing, chemical stability, and photoresponsive properties. However, most of the known lead-free hybrids show wide band gaps (Eg > 1.9 eV) that afford weak visible-light absorption. Here, we show a newly conceptual design strategy of intercalating triiodide to decrease the prototypic band gap by ca. ∼0.44 eV. A new hybrid semiconducting material of (4-methylpiperidinium)4·I3·BiI6 (MP-T-BiI6), adopting the zero-dimensional (0D) perovskite-like framework, was reconstructed from its prototype of (4-methylpiperidinium)3Bi2I9 (MP-Bi2I9). It is noteworthy that MP-T-BiI6 has a narrow band gap of 1.58 eV, almost comparable to that of CH3NH3PbI3 (∼1.5 eV), which reveals its potential as the highly efficient light absorber. Importantly, its semiconducting properties were solidly confirmed by notable hole mobility (∼12.8 cm2 V–1 s–1), charge-trap density (∼1.13 × 1010 cm–3), and photoconductive behaviors. ...

Significant progress on a new brilliant scheme for the solid phase transition has opened up new possibilities of highly efficiently switching the quadratic nonlinear optical (NLO) properties. However, the NLO switching capacities of previously reported solid-state materials were restrictively modulated between the conventional bistable states. Exploring NLO tristability is strongly required for multistep operations in multilevel memory elements and optoelectronic devices. Here, we first report a tristable molecule-based dielectric, dipropylammonium trichloroacetate (DPA-TCA), which shows an exceptional three-level switching of quadratic NLO effects (i.e., NLO-off, low-NLO, and high-NLO states). This unprecedented three-level switching of the NLO effect originates from the stepwise ordering of the dynamic molecular components in DPA-TCA, associated with the tristability of dielectric phase transitions at 142 and 228 K. It is believed that this finding will shed light on the further design of new multilevel...

Highly controllable photoelectric switches are urgently demanded in the field of nonlinear optics. In the present work, high-performance quadratic molecular nonlinear optical (NLO)-switches based on organic hydrogen-bonded ferroelectric materials, showing large contrasts (up to ∼68%), tunable reversibility, and superior switching “on–off” time, were first prepared from the highly oriented thin polymer films, which overcome the stability problems of the conventional photochromic counterparts and throw light on the further research of NLO-switching materials from the emerging field of organic molecular ferroelectrics.