Temperature‐Dependent Excitonic Band Gap in Lead‐Free Bismuth Halide Low‐Dimensional Perovskite Single Crystals

Advanced Optical Materials, Journal Year: 2023, Volume and Issue: 12(11)

Published: Dec. 24, 2023

Abstract In this study, the optical behavior of lead‐free Bi‐based low‐dimensional perovskite single crystals (Cs 3 Bi 2 Cl 9 , Cs Br I and MA ) is investigated by spectroscopic ellipsometry, supported X‐ray diffraction density functional theory calculations. All materials exhibit a strong excitonic peak resulting from photogenerated electron–hole Coulomb interactions, whereas threshold continuous absorption found at higher energies. The resonances bands, along with exciton binding energies, are extracted through Critical Point Analysis ellipsometric data over wide temperature range (from −90 °C to 90 °C), revealing subtle variations in characteristics for each crystal. These can be applied optoelectronics as photodetectors because their high stability lower toxicity compared Pb‐based perovskites.

Language: Английский

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Methanol‐Induced Crystallization of Chiral Hybrid Manganese (II) Chloride Single Crystals for Achieving Circularly Polarized Luminescence and Second Harmonic Generation

Advanced Optical Materials, Journal Year: 2023, Volume and Issue: 12(2)

Published: Aug. 17, 2023

Abstract Chiral hybrid Mn (II)‐based halides have attracted great interest in the optoelectronic field due to their low cost, non‐toxicity, abundant structural diversity, and excellent photoluminescence, chiroptical, nonlinear optical characteristics. Here, chiral hybrids (R/S‐MBA)MnCl 3 ·CH OH (MBA = C 6 H 5 CH(CH )NH + ) (R/S‐NPA)Cl·H 2 O (R, S‐NPA)Cl (NPA 10 7 single crystals are successfully obtained using methanol (CH OH) as an induced‐crystallization reagent by slow evaporation method. Interestingly, with obvious circular dichroism (CD) characteristics exhibit strong red emission originating from d‐d transition of 2+ cation, while (R/S‐NPA) Cl·H blue organic NPA group. Based on space group P 1 (no.4), show circularly polarized luminescence (CPL) a relatively high dissymmetry factor ( g lum value, which is equivalent that reported metal halides. Also, second harmonic generation (SHG) response. This work not only deepens understanding role methanol‐induced crystallization improving quality growth habits halide crystals, but also provides guidance for further design, crystal growth, applications multi‐functional materials.

Language: Английский

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Self‐Charging Power System Empowered by Bismuth Halide Perovskite‐Based Hybrid Nanogenerator and Lithium‐ion Battery

Small, Journal Year: 2024, Volume and Issue: unknown

Published: May 19, 2024

Abstract Halide perovskite, renowned for its multifunctional properties, shows considerable promise realizing self‐charging power systems. In this study, a lead‐free methylammonium bismuth iodide (MA 3 Bi 2 I 9 ) perovskite is used to create unit (SPU). This involves constructing hybrid piezoelectric‐triboelectric nanogenerator (Hybrid‐TENG) and utilizing MA energy storage as an anode in lithium‐ion battery (LIB). Initially, nanorods are synthesized composited with polystyrene‐block‐poly(ethylene‐ran‐butylene)‐block‐polystyrene polymer. The dielectric mechanical properties of composite films having loading content investigated. optimized Hybrid‐TENG exhibits superior performance, generating voltage 537 V, current density 13.2 µA cm − , maximum 3.04 mW −2 which can be attributed the high piezoelectric coefficient (≈20.6 pm V −1 ). A thin film, serving electrode LIB, demonstrates specific capacity 2378.9 mAh −3 (578.8 g retention ≈87.5% over 100 cycles, underscoring stable performance. Furthermore, employed charge ‐based thus SPU driving portable electronics. study highlights promising potential perovskites developing efficient nanogenerators LIBs, paving way sustainable solutions small‐scale

Language: Английский

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X‐ray‐ultraviolet–visible‐near‐infrared photoresponses realized in a lead‐free hybrid perovskite ferroelectric through light‐induced ferro‐pyro‐phototronic effect

InfoMat, Journal Year: 2024, Volume and Issue: 6(10)

Published: July 1, 2024

Abstract Due to the built‐in electric field induced by spontaneous polarization in hybrid perovskite (HP) ferroelectrics, devices based on them exhibit excellent performance self‐powered photodetection. However, most of photodetector are made lead‐based HP ferroelectrics and have a relatively narrow photoresponse waveband. Although lead‐free HPs solve problem lead toxicity, their optoelectronic is inferior that waveband limited its optical band gap, which hinders further application. To this problem, herein, ferroelectric (HDA)BiI 5 (HDA hexane‐1,6‐diammonium) with large shows an enhanced photocurrent achieves x‐ray‐ultraviolet–visible‐near‐infrared (x‐ray‐UV–Vis–NIR) through ferro‐pyro‐phototronic (FPP) effect. The ferroelectric, pyroelectric, photovoltaic characteristics coupled together single‐phase effective way improve devices. What particularly attractive FPP effect not only improves , but also broadband photoresponses beyond absorption range. Especially, current boosting exceptional contrast ~1100% 2400% under 520 637 nm, respectively, associated Meanwhile, single crystal significant effects even high‐energy x‐ray, owns outstanding sensitivity 170.7 μC Gy −1 cm −2 lower detection limit 266 nGy s at 0 V bias. Therefore, it great significance study coupling multiple physical device ferroelectrics. image

Language: Английский

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Improvement of photovoltaic response in perovskite solar cell via all inorganic lead free cubic double La2NiMnO6/Cs3Bi2I9 based graded absorber architecture

Optical and Quantum Electronics, Journal Year: 2024, Volume and Issue: 56(8)

Published: July 18, 2024

Language: Английский

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