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Due to the enhanced ambient structural stability and excellent optoelectronic properties, all-inorganic metal halide perovskite nanowires have become one of the most attractive candidates for flexible electronics, photovoltaics and optoelectronics. Their elastic property and mechanical robustness become the key factors for device applications under realistic service conditions with various mechanical loadings. Here, we demonstrate that high tensile elastic strain (∼ 4% to ∼ 5.1%) can be achieved in vapor-liquid-solid-grown single-crystalline CsPbBr3 nanowires through in situ scanning electron microscope (SEM) buckling experiments. Such high flexural elasticity can be attributed to the structural defect-scarce, smooth surface, single-crystallinity and nanomechanical size effect of CsPbBr3 nanowires. The mechanical reliability of CsPbBr3 nanowire-based flexible photodetectors was examined by cyclic bending tests, with no noticeable performance deterioration observed after 5,000 cycles. The above results suggest great application potential for using all-inorganic perovskite nanowires in flexible electronics and energy harvesting systems. [ABSTRACT FROM AUTHOR]

Hybrid organolead halide perovskites have attracted tremendous attention due to their recent success as high efficiency solar cell materials and their fascinating material properties uniquely suitable for optoelectronic devices. However, the poor ambient and operational stability as well as the concern of lead toxicity greatly hamper their practical utilization. In this work, crystalline, all-inorganic and lead-free Cs3Sb2I9 perovskite microplates are successfully synthesized by a two-step chemical vapor deposition method. As compared with other typical lead-free perovskite materials, the Cs3Sb2I9 microplates demonstrate excellent optoelectronic properties, including substantial enhancements in the Stokes shift, exciton binding energy and electron-phonon coupling. Simple photoconductive devices fabricated using these microplates exhibit an ultra-fast response with the rise and decay time constants down to 96 and 58 µs, respectively. This respectable photoconductor performance can be regarded as a record among all the lead-free perovskite materials. Importantly, these photodetectors show superior thermal stability in a wide temperature range, capable to function reversibly between 80 and 380 K, indicating their robustness to operate under both low and high temperatures. All these results evidently suggest the technological potential of inorganic lead-free Cs3Sb2I9 perovskite microplates for next-generation high-performance optoelectronic devices. [ABSTRACT FROM AUTHOR]

Due to the ultra-thin nature and moderate carrier mobility, semiconducting two-dimensional (2D) materials have attracted extensive attention for next-generation electronics. However, the gate bias stress instability and hysteresis are always observed in these 2D materials-based transistors that significantly degrade their reliability for practical applications. Herein, the origin of gate bias stress instability and hysteresis for chemical vapor deposited monolayer WS2 transistors are investigated carefully. The transistor performance is found to be strongly affected by the gate bias stress time, sweeping rate and range, and temperature. Based on the systematical study and complementary analysis, charge trapping is determined to be the major contribution for these observed phenomena. Importantly, due to these charge trapping effects, the channel current is observed to decrease with time; hence, a rate equation, considering the charge trapping and time decay effect of current, is proposed and developed to model the phenomena with excellent consistency with experimental data. All these results do not only indicate the validity of the charge trapping model, but also confirm the hysteresis being indeed caused by charge trapping. Evidently, this simple model provides a sufficient explanation for the charge trapping induced gate bias stress instability and hysteresis in monolayer WS2 transistors, which can be also applicable to other kinds of transistors. [ABSTRACT FROM AUTHOR]