Research
研究方向
课题组主要利用拉曼、荧光、超快光谱等光谱学手段研究低维材料的基本物理性质,并通过缺陷、应变和界面工程调控其光电特性,致力于发展高性能光电探测、发光与光伏器件。
01低维材料光谱学研究
光谱技术高效、无损,空间分辨率可通过聚焦激光从亚微米调节到厘米量级,是研究低维材料的有力工具。 我们发展了光学衬度谱技术以精确判定二维材料层数(最多 10 层),利用拉曼和荧光光谱研究低维材料的缺陷、掺杂与电子能带结构, 并采用时间分辨荧光、光泵浦-光/太赫兹探测等超快光谱研究其载流子动力学与光电性质。
代表性论文
- Ni ZH et al. Graphene thickness determination using reflection and contrast spectroscopy. Nano Letters 7, 2758 (2007)
- Ni ZH et al. On resonant scatterers as a factor limiting carrier mobility in graphene. Nano Letters 10, 3868 (2010)
- Liu HW et al. Composition-dependent electron transport in CdSxSe1-x nanobelts, a THz spectroscopy study. Optics Letters 39, 567 (2014)
- Wu ZT et al. Defects as a factor limiting carrier mobility in WSe2, a spectroscopic investigation. Nano Research 9, 3622 (2016)
02二维材料光学性质调控
光电应用要求材料具有合适的带隙、高迁移率和强光吸收。我们致力于通过调控层间相互作用、边缘手性、应变和缺陷工程等手段, 调控石墨烯及其他二维材料的光学性质,以满足各类器件的需求。
代表性论文
- Ni ZH et al. Tunable stress and controlled thickness modification in graphene by annealing. ACS Nano 2, 1033 (2008)
- Liu YL et al. Layer-by-layer thinning of MoS2 by plasma. ACS Nano 7, 4202 (2013)
- Nan HY et al. Strong photoluminescence enhancement of MoS2 through defect engineering and oxygen bonding. ACS Nano 8, 5738 (2014)
- Lu JP et al. Bandgap engineering of phosphorene by laser oxidation toward functional 2D materials. ACS Nano 9, 10411 (2015)
03激光微纳加工
低维纳米材料尺寸极小,精确操控是制约其实际应用的难题。激光具有空间分辨率高、能量密度高、灵活等特点, 可作为操控、结构转变、微图形化和化学改性的通用工具。我们设计并优化了激光加工技术,实现了低维材料的激光图形化、减薄、改性与表面修饰。
代表性论文
- Lu JP et al. Improved photoelectrical properties of MoS2 films after laser micromachining. ACS Nano 8, 6334 (2014)
- Lu JP et al. Atomic healing of defects in transition metal dichalcogenides. Nano Letters 15, 3524 (2015)
- Lu JP et al. Microlandscaping of Au nanoparticles on few-layer MoS2 films for chemical sensing. Small 11, 1792 (2015)
- Lu JP et al. Enhanced photoresponse from phosphorene–phosphorene-suboxide junction fashioned by focused laser micromachining. Advanced Materials 28, 4090 (2016)
04光电性质与器件
光电器件是二维材料最有前景的应用之一,包括光探测、发光和光伏器件。我们与合作者一起发展了一系列基于二维材料的光电器件, 如石墨烯锁模激光器与光学偏振器、高性能光电探测器以及位置敏感探测器。
代表性论文
- Wang WH et al. High performance position-sensitive-detector based on graphene–silicon heterojunction. Optica 5, 27 (2018)
- Guo XT et al. High-performance graphene photodetector using interfacial gating. Optica 3, 1066 (2016)
- Lu JP et al. Hybrid bilayer WSe2–CH3NH3PbI3 organolead halide perovskite as a high-performance photodetector. Angew. Chem. Int. Ed. 55, 11945 (2016)
- Wang WH et al. Interfacial amplification for graphene based position sensitive detectors. Light Sci. Appl. 6, e17113 (2017)