Electronic Materials Letters最新文献

This study demonstrates a simple centrifugal coating method to prepare high-quality pure cubic phase CsPbBr₃ nanocrystal film. The resultant perovskite layers possess a uniform and dense 500 nm-thick, with a bandgap of 2.38 eV, a low trap-state density of 6.9 × 10^− 15 cm^− 3, and carrier mobility of approximately 19.8 cm²V^− 1s^− 1. Furthermore, CsPbBr₃ NCs-based self-powered photodetectors with high charge carriers’ charge transfer are fabricated. The device shows a low dark current density of 1.93 × 10^− 7 A/cm² at room temperature. Such photodetectors show the highest responsivity of 3.0 AW^− 1, specific detectivity of 1.2 × 10¹³ Jones, and external quantum efficiency (EQE) of 920% at zero bias voltage. The proposed method shows significant promise for use in the lab fabrication of optoelectronic devices based on thin films of nanocrystal perovskite materials.

WO₃ thin films were prepared on indium-tin oxide (ITO) glass substrates at different substrate temperature by radio frequency magnetron sputtering. Then the films were soaked in five organic solvents of acetone, ethanol, cyclohexane, acetonitrile and ethyl acetate for 48 h, respectively. The changes in the microstructure, surface morphology and electrochromic (EC) properties of WO₃ thin films before and after the immersion treatment were systematically studied. It was found that after soaking in ethanol, the optical modulation of amorphous WO₃ thin films deposited at room temperature increased from 50 to 85%, showing excellent EC performance. Moreover, the immersion treatment in ethanol is also helpful for improving the EC properties of amorphous WO₃ thin films prepared at elevated substrate temperature. However, after immersion in the other organic solvents, the optical modulation of WO₃ thin films increased less (for acetone: 77%) or even decreased significantly (for cyclohexane, acetonitrile and ethyl acetate: 31%, 30% and 35%, respectively). In addition, the immersion treatment in ethanol cannot improve the optical modulation of crystalline WO₃ thin films prepared at 600 °C, which dropped from 58 to 40%. The authors believe that this is mainly related to the different dredging effects of various organic solvents on the transport channels of Li-ions and electrons in WO₃ thin films. Therefore, this work provides a new approach for the optimization of EC performance of amorphous WO₃ thin films.

Efforts to improve the properties of composites have involved extensive studies regarding the effective incorporation of a polymer matrix and inorganic fillers. In this work, we generated a stable organosilica sol with high concentration and high purity by surface modification with silane coupling agents, then integrated it with an epoxy matrix. The silica nanoparticle/epoxy composite exhibited improved tensile strength because of the uniform distribution of silica in the matrix, as well as the interfacial chemical bonding between polymer and silica nanoparticles; these factors resulted in effective load transfer from matrix to fillers. Additionally, the application of copper-clad laminates (CCLs) with prepreg-containing silica nanoparticles led to substantial improvements in mechanical properties, including peel strength (0.46 kgf/cm) and storage modulus (30.0 GPa), compared with conventional CCLs lacking silica nanoparticles. These results suggest that prepregs containing surface-modified silica nanoparticles have great potential for use as printed circuit board substrate materials in high-performance electronics.

The effect of electron-beam irradiation (EBI) on MoS₂-based photodetectors with various electrode structures was investigated to improve the electrical and photoelectrical properties. The MoS₂ films were deposited at room temperature by RF magnetron sputtering and subsequently transformed into a two-dimensional layered structure by EBI treatment with the electron energy of 3 kV for 1 min. The electrical resistance and photoelectrical properties, such as photocurrent and photoresponsivity, of MoS₂ films were examined with patterned Au/Ti electrodes as a top contact (TC) and a bottom contact structure. In addition, the interfacial effect of high-k dielectric materials of thin HfO₂ film between MoS₂ and the SiO₂/Si substrate was investigated to enhance the photoelectrical property. The MoS₂ photodetectors fabricated by the EBI before TC formation on HfO₂ exhibited the highest photoresponsivity of 11.88 mA/W, which was an increase of 6500% from the EBI before TC structure on SiO₂. We believe that this work contributes to the improvement of contact and interface properties of MoS₂-based photodetectors readily and quickly compared with conventional high-temperature thermal treatment.