二维铁电材料α-In2Se3 表面分子束外延生长Pb 纳米岛的STM 研究

铁电材料拥有自发电极化, 不同的极化方向会对异质结的电子结构产生可逆的和非易失性的影响. 本工作采用分子束外延技术在二维铁电材料α-In2Se3 衬底上成功制备了 Pb 纳米岛构建 Pb/α-In2Se3 超导铁电异质结,并通过扫描隧道显微镜表征了其表面原子结构与电子结构. 进一步的扫描隧道谱测量显示不同层厚 Pb 岛的量子阱态消失, 并且我们在4.5 K 的温度下没有观察到超导能隙, 表明铁电衬底会影响 Pb 岛的电子结构, 甚至其超导特性. 这些发现为理解铁电衬底对超导性的影响提供了参考, 并为调控低维量子材料中的电子结构及超导性提供了新的思路.     

Al纳米颗粒表面等离激元对ZnO光致发光增强的研究

基于聚苯乙烯球自组装法,在P型氮化镓(P-GaN)衬底上制备了有序致密的掩模板;采用热蒸发法在该模板上沉积金属Al薄膜,通过甲苯溶液去除聚苯乙烯球,得到了金属Al纳米颗粒阵列;采用原子层沉积法,在Al纳米颗粒阵列表面依次沉积氧化铝(Al_2O_3)和氧化锌(ZnO).通过测试Al纳米颗粒阵列的消光谱以及ZnO薄膜的光致发光谱,研究了Al纳米颗粒表面等离激元与ZnO薄膜激子之间的耦合效应.实验结果表明:引入Al纳米颗粒后,在约380 nm位置附近的ZnO近带边发光峰积分强度增强了1.91倍.对Al纳米颗粒表面等离激元增强ZnO光致发光的机理进行探讨.     

钯催化下肟醚导向的sp~2 C—H键邻位酰氧化反应(英文)

使用醋酸钯作为催化剂,过硫酸钠和氧化银为氧化剂,使肟醚导向的底物与苯甲酰甲酸发生sp2C—H键的邻位酰氧化反应,从而得到芳香酮类化合物.该方法对带吸电子基和给电子基的反应物都有很好的适应性,最高产率可达98%.     

Two-dimensional Sb cluster superlattice on Si substrate fabricated by a two-step method

Nanoclusters consisting of a few atoms have attracted a lot of research interests due to their exotic size-dependent properties. Here, well-ordered two-dimensional Sb cluster superlattice was fabricated on Si substrate by a two-step method and characterized by scanning tunneling microscopy. High resolution scanning tunneling microscope measurements revealed the fine structures of the Sb clusters, which consist of several Sb atoms ranging from 2 to 7. Furthermore, the electronic structure of the nanocluster displays the quantized energy-level which is due to the single-electron tunneling effects. We believe that the fabrication of Sb cluster superlattice broadens the species of the cluster superlattice and provides a promising candidate to further explore the novel physical and chemical properties of the semimetal nanocluster.