报告时间：7月16日上午9:30

报告地点：科技创新大楼C501室

报告题目：Inorganic-Organic Perovskite Nanolaser

Abstract:

Inorganic-Organic Perovskite Nanolasers
Qihua Xiong
School of Physical and Mathematic Sciences & School of Electrical and Electronic Engineering
Nanyang Technological University, Singapore, 637371

Solid-state micro/nanolasers are important building blocks for true integration of optoelectronic circuitry. Although significant progress has been made in III-V nanowire lasers with achieving near-infrared (NIR) lasing at the room-temperature, challenges remain including low quantum efficiencies and high Auger losses. Here we demonstrate a new family of planar room-temperature NIR nanolasers based on organic-inorganic perovskite CH3NH3PbIaX3-a (X= I, Br, Cl) nanoplatelets [1, 2]. Well-defined polygonal crystalline perovskite nanoplatelets are grown on mica substrates by chemical vapour methods, which naturally forms high-Q whispering-gallery-mode cavity. Their high quantum yield and long diffusion lengths and naturally formed high-quality planar whispering-gallery mode cavities ensure adequate gain and efficient optical feedback for low-threshold optically pumped in-plane lasing. Further, we synthesize pervoskite nanoplateletes and nanowires [3] with varied bandgap from ultra-violet to near-infrared and demonstrate wide-band tunable lasing based on the structures. Our findings open up a new class of wavelength tunable nanomaterials potentially suitable for on-chip integration and flexible optoelectronic devices.

References:

[1] Q. Zhang, S.T. Ha, X.F. Liu, T.C. Sum* and Q.H. Xiong*, "Room-Temperature Near-Infrared High-Q Perovskite Whispering-Gallery Planar Nanolasers", Nano Lett. 14(10), 5995–6001 (2014)
[2] S.T. Ha, X.F. Liu, Q. Zhang, D. Giovanni, T. C. Sum and Q.H. Xiong*, "Synthesis of Organic–Inorganic Lead Halide Perovskite Nanoplatelets: Towards High-Performance Perovskite Solar Cells and Optoelectronic Devices”, Adv. Opt. Mater. 2, 838-844 (2014)
[3] J. Xing, X. F. Liu, Q. Zhang and Q. H. Xiong*, “Vapor Phase Synthesis of Organometal Halide Perovskite Nanowires for Tunable Room-Temperature Nanolasers”, Nano Lett. (in press), 2015.

Short Biography:

Qihua Xiong received his B.Sc. degree in Physics from Wuhan University in 1997, and then finished three years graduate studies at Shanghai Institute of Applied Physics, Chinese Academy of Sciences. In 2006, he obtained his Ph.D. degree under the supervision of Prof. Peter C. Eklund from The Pennsylvania State University. After three years postdoctoral experience in Prof. Charles M. Lieber’s group at Harvard University, he joined Nanyang Technological University as an assistant professor in 2009. He is a Fellow of Singapore National Research Foundation awarded in 2009. He was promoted as Nanyang Associate Professor and awarded the prestigious Nanyang Award for research excellence in 2014. Recently, he was awarded the inaugural NRF Investigatorship Award by Singapore National Research Foundation. Prof. Xiong’s research focuses electrical and optical properties of semiconductor nanomaterials and plasmonics, 2D layered semiconductor materials and laser cooling of solids.