Hao Jinqian, Tai Guoan, Zhou Jianxin, Wang Rui, Hou Chuang, Guo Wanlin
The State Key Laboratory of Mechanics and Control of Mechanical Structures, Laboratory of Intelligent Nano Materials and Devices of Ministry of Education, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
School of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
ACS Appl Mater Interfaces. 2020 Apr 15;12(15):17669-17675. doi: 10.1021/acsami.9b19648. Epub 2020 Mar 31.
Zero-dimensional boron structures have always been the focus of theoretical research owing to their abundant phase structures and special properties. Boron clusters have been reported extensively by combining structure searching theories and photoelectron spectroscopy (PES) experiments; however, crystalline boron quantum dots (BQDs) have rarely been reported. Here, we report the preparation of large-scale and uniform crystalline semiconductor BQDs from the expanded bulk boron powders via a facile and efficient probe ultrasonic approach in the acetonitrile solution. The obtained BQDs have 2.46 nm average lateral size and 2.81 nm thickness. Optical measurements demonstrate that a strong quantum confinement effect occurs in the BQDs, implying the increase of the band gap from 1.80 eV for the corresponding bulk to 2.46 eV for the BQDs. By injecting the BQDs into poly(vinylpyrrolidone) as an active layer, a BQD-based memory device is fabricated that shows a rewriteable nonvolatile memory effect with a low transition voltage of down to 0.5 V and a high on/off switching ratio of 10 as well as a good stability.
零维硼结构因其丰富的相结构和特殊性质一直是理论研究的焦点。通过结合结构搜索理论和光电子能谱（PES）实验，硼团簇已被广泛报道；然而，晶体硼量子点（BQDs）却鲜有报道。在此，我们报道了通过在乙腈溶液中采用简便高效的探针超声方法，由膨胀的块状硼粉制备大规模且均匀的晶体半导体BQDs。所获得的BQDs平均横向尺寸为2.46 nm，厚度为2.81 nm。光学测量表明，BQDs中出现了强烈的量子限制效应，这意味着带隙从相应块状材料的1.80 eV增加到BQDs的2.46 eV。通过将BQDs注入作为活性层的聚（乙烯基吡咯烷酮）中，制备了一种基于BQD的存储器件，该器件显示出可重写的非易失性存储效应，具有低至0.5 V的低转变电压和高达10的高开关比以及良好的稳定性。
