CHEMICAL PHYSICS LETTERS
·
2023
·
IF 2.8
Bo Zhang,Shuo Ding,Xuanyu Zhang,Lei Qian,Chaoyu Xiang
Due to the deep energy levels, the external quantum efficiency (EQE) of the blue perovskite light-emitting diode (PeLED) is far lower than its green, red, and near-infrared counterparts, which has exceeded 20%. The mismatched energy levels between perovskites and the hole transporting layer (HTL) still hinder the hole injection and consequent improvement of blue PeLED device performance. Here, a two-dimensional material, WS 2 (Tungsten disulfide), was introduced to match the energy levels between perovskites and HTL and enhanced the hole injection. The WS 2 HTL-based perovskite FAPbBr 3-x Cl x blue LED achieved a luminance of 990 cd/m 2 with an EQE of 3.24%, which surpasses the performance of previously reported for the formamidinium (FA) based system, indicating the potential of WS 2 for PeLEDs.
研究领域:
材料科学
·
光电
·
半导体器件
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Tiantian Chen,Jie Chen,Zhenyu Yi,Congqin Zheng,Linming Zhou,Yongjun Wu,Feiyan Cai,Jiale Qin,Zijian Hong,Yuhui Huang
Transcranial ultrasound imaging and therapy have gained significant attention due to their noninvasive nature, absence of ionizing radiation, and portability. However, the presence of the skull, which has a high acoustic impedance, presents a challenge for the penetration of ultrasound into intracranial tissue. This leads to a low transmission of ultrasound through the skull, hindering energy focusing and imaging quality. To address this challenge, we propose a novel approach that utilizes a flexible matching layer with gradual acoustic impedance to enhance ultrasound transmission through the skull. This matching layer is constructed using Poly(dimethylsiloxane) (PDMS)/tungsten powders as the structural component responsible for the gradual impedance, while agarose serves as the flexible matrix. Our simulation and experimental results demonstrate that the matching layer with an exponential gradual acoustic impedance significantly improves the ultrasound transmission coefficient across a wide frequency range compared to traditional quarter wavelength matching layers. Specifically, at 2 MHz, the maximum transmission coefficient reaches 49.5%, more than four times higher than that of the skull without a matching layer (only 11.7%). Additionally, the good flexibility of our matching layer ensures excellent adhesion to the curved surface of the skull, further enhancing its application potential in transcranial ultrasound imaging and therapy. The improved transmission performance allows for a lower ultrasound transmission power, effectively addressing overheating and safety issues.
研究领域:
医学成像
·
生物医学工程
·
超声治疗
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2024
·
IF 4.2
Xin Shao,Siqi Han,Yang Kang,Xuewen Yang,Lin Yang,Qihan Zhang,Xiaomin Wang
The plasma-silane coupling agent synergistically modified the hollow glass microsphere (HGM) process, blended with epoxy resin (EP), to prepare an acoustic matching layer suitable for the gas ultrasonic transducers. In comparison to the traditional NaOH solution stirring co-hydroxylation process, the plasma treatment method can rapidly activate the surface activity of HGM, leading to the generation of a large number of hydroxyl groups on the HGM surface. This process eliminates the need for mechanical stirring and cleaning steps, thus reducing the damage degree of HGM and the loss degree of surface hydroxyl groups . The results indicate that the amination modification effect of HGM treated with plasma is more pronounced, and the HGM/EP composite material exhibits better compatibility and density. The assembled ultrasonic transducer exhibits a sensitivity of up to 1.58 V, showing an improvement of nearly 61.2 % compared to the reference ultrasonic transducer with a sensitivity of 0.98 V. Furthermore, the calibrated testing of the gas ultrasonic flowmeter using the improved ultrasonic transducer demonstrates a percentage error absolute value below 0.7 % and a measurement result standard deviation below 0.15 %, demonstrating better measurement accuracy and consistency. This study aims to provide a new feasible process for improving the performance of gas ultrasonic transducers and ultrasonic flowmeters.
研究领域:
材料科学
·
声学工程
·
流体力学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry B
·
2025
·Vol. 13
·期 9
·3023-3031
·
IF 5.7
Jiaqi Wu,Yichi Zhang,Yue Liu,Yuanyuan Zheng,Kailiang Xu,Peining Chen,Huisheng Peng
Acoustic matching layers play an important role in ultrasonic transducers. However, the acoustic matching layer with both intrinsic flexibility and high acoustic impedance remains an unmet need to achieve high-performing flexible ultrasonic transducers. Herein, we present an epoxy/nano-zirconia composite with excellent flexibility and acoustic performance by the chemical coupling method. (3-Aminopropyl)triethoxysilane was used to effectively disperse nano-zirconia particles in epoxy resin, and endow the resultant composite with flexibility. After carefully adjusting the additions of nano-zirconia particles and (3-aminopropyl)triethoxysilane, the modulus of the epoxy/nano-zirconia composite was 4.5 MPa, combined with an elongation at break over 90%. The acoustic impedance of the epoxy/nano-zirconia composite (∼4.5 MRayl) exceeded that of other typical polymer counterparts. The flexible acoustic matching layer based on an epoxy/nano-zirconia composite could significantly improve the sensitivity and bandwidth of ultrasonic transducers. A fiber-shaped ultrasonic transducer with high sensitivity and wide bandwidth was fabricated, displaying promising application potential in wearable medical electronics.
研究领域:
材料科学
·
声学
·
纳米技术
·
生物医学工程
·
高分子科学
·
电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）