Band gaps are one of the most important parameters of semiconductor materials for their optoelectronic applications since they determine the spectral features of absorptions and emission processes [1,2]. Due to the limited band gaps of natural semiconductors, alloying and heterostructured semiconductors with different band gaps have long been the standard methods of achieving semiconductor structures with new band gaps and functions [3,4]. In this talk, I will report our recent progress on the band gap engineering of 1D semiconductor nanowires and 2D atomically thin layered materials through controlled vapor growth. Using some examples, I will show how to realize composition graded and interface sharped low dimensional semiconductor heterostructures through composition controlled band gap modulation. The achieved band gap engineered nanostructures can give continuously tuned or white light emission, and can be used to realize multi-color nanolasers, wavelength splitter, asymmetric waveguiding and high-performance photodetectors etc [5-7].

References

[1] Hong Zhou, Shuangping Yuan, Anlian Pan et al., Vapor Growth and Tunable Lasing of Band Gap Engineered Cesium Lead Halide Perovskite Micro/Nanorods with Triangular Cross Section. ACS Nano, 2017, 11 (2), pp 1189-1195.
[2] Honglai Li, Xueping Wu, Anlian Pan et al., Composition-Modulated Two-Dimensional Semiconductor Lateral Heterostructures via Layer-Selected Atomic Substitution, ACS Nano, 2017, 11, 961-967.
[3] Xidong Duan, Anlian Pan, Xiangfeng Duan et al., Synthesis of WS_2xSe_2–2x Alloy Nanosheets with Composition-Tunable Electronic Properties, Nano Lett. 2016, 16 (1), pp 264-269.
[4] Xidong Duan, Anlian Pan, Xiangfeng Duan et al.. Two-dimensional transition metal dichalcogenides as atomically thin semiconductors: opportunities and challenges, Chem. Soc. Rev., 2015, 44, 8859-8876.
[5] Honglai Li, Anlian Pan, Xiangfeng Duan et al., Lateral growth of composition graded atomic layer MoS_2(1-x)Se_2x nanosheets, J. Am. Chem. Soc., 2015, 137, 5284-5287.
[6] Xidong Duan, Anlian Pan, Xiangfeng Duan et al., Lateral epitaxial growth of two-dimensional layered semiconductor heterojunctions, Nature Nanotechnology, 2014, 9,1024-1030.
[7] Pengfei Guo, Xiujuang Zhuang, Anlian Pan et al., Semiconductor Alloy Nanoribbon Lateral Heterostructures for High-performance Photodetectors, Adv. Mater., 2014, 26, 2844-2849.