（1）主題：Rational design of colloidal heterostructured core/shell quantum dots for solar technologies
（2）主講人： 童鑫 基礎與前沿研究院博士后
Ternary I–III–VI2 colloidal CuGaS2 (CGS) quantum dots (QDs) have attracted much attention in various solar technologies due to their high absorption coefficient and size/shape/composition-tunable optical properties. However, the bare CGS QDs possess limited light absorption and abundant defects/traps which hinder their capability of serving as light harvesters because of poor photo-conversion efficiency. The rational design and synthesis of heterostructured QDs such as core/shell QDs is beneficial to passivate the surface defects/traps and tune their optical properties. Herein, we reported the synthesis of CGS/CdS core/shell QDs with optimized optoelectronic properties and their application in high efficiency and stable solar-driven QDs-based photoelectrochemical (PEC) cells. The results are indicative of the promising future of this CGS/CdS core/shell QDs in other QD-based optoelectronic devices such as QD-sensitized solar cells (QDSCs).
Xin Tong currently works as a Postdoctoral Fellow in the Institute of Fundamental and Frontier Sciences of University of Electronic Science and Technology of China (UESTC). He obtained his bachelor’s degree in Electronic Science and Technology and his Ph.D. degree in Materials Science and Engineering from UESTC in 2014 and 2018, respectively. His research interests focus on the design and synthesis of colloidal quantum dots and their applications in solar technologies.
（1） 主題：Spectrally Pure-State Generation from integrated lithium niobite waveguide at telecom Wavelength
In this talk, we briefly discuss the biphoton state generated from the third-order nonlinear optical process in the integrated lithium niobite waveguide on insulator at telecom Wavelength. Here, the phase-matching function and three kinds of group-velocity matching conditions have been analysed for the generation of spectrally uncorrelated biphoton-state at 1.55mm. The purity of the single photon is as high as 0.96. Otherwise, the manipulation of the biphoton-state is discussed through varying the angle between optical axis of lithium niobite and propagating direction of waveguide.
Boyu Fan received the Bachelor degree and Ph.D. degree from the Tsinghua University, in 2008 and 2013, respectively. He currently works as a Postdoctoral Fellow in the School of Institute of Fundamental and Frontier Sciences of UESTC. Dr. The main research interests of Dr. Fan include Surface Plasmon Polariton; integrated lithium niobite devices; integrated quantum devices.
（1）主題：Nanowire quantum dot surface engineering for high temperature single photon emission
Generating single photons at high temperature remains a major challenge, particularly for the arsenide and phosphide compounds widely used in optical communication. Here, we reports a high-temperature single photon emitter based on a “surface-free” GaAs quantum dot in a GaAsP nanowire. By using self-catalyzed vapor-liquid-solid growth and facile solution-based surface passivation, we avoided contamination and defects possibly detrimental to achieve high emperature single photon source. The nanowire quantum dot generates intense and highly polarized photoluminescence at 750 nm after surface treatment. A cathodoluminescence indicates this nanowire quantum dot has a possibility operating at room temperature if it is electrically pumped. The “surface-free” nanowire quantum dot shows efficient photon antibunching was observed up to 160 K and well resolved exciton lines as high as 220 K, respectively. This is one of the very few quantum dot single photon emitter around 750 nm which is highly desired due to the high sensitivity of mature single photon detectors. More importantly, to the best of our knowledge, this work demonstrates the highest operating temperature of III-V single photon emitters in the optical communication wavelengths.
Peng Yu is currently a group leader of Plasmonic photonics in group of Prof. Zhiming Wang (IMD) in the Institute of Fundamental and Frontier Sciences of University of Electronic Science and Technology of China. He obtained his bachelor’s degree in Microelectronics in 2012 and master’s degree in Electronic Information Materials and Components in 2015 and Ph.D degree in 2018. His current research interests include plasmonics, plasmon-enhanced light-harvesting devices, plasmon-enhanced light-emitting devices.
（1）主題：Suppressing Hydrogen Evolution Reaction in the Reduction of Dinitrogen to Ammonia under Ambient Conditions
Ammonia is critical for the production of fertilizers. It is mainly produced by the traditional Haber-Bosch process, which consumes massive amounts of energy under the high-temperature and -pressure operations. The reduction of N2 to NH3 with the lower energy consumption under the mild aqueous conditions is one of the most attractive topics recently in the field of chemistry. However, one major challenge is to achieve high yield efficiency due to the competing hydrogen evolution reaction (HER). In this talk, we briefly describe the recent progress towards the reaction mechanisms of nitrogen reduction reaction and the strategies to suppress the HER based upon some typical researches.
Shijia Mu received the Bachelor degree from Southwest University and Ph.D. degree from Sichuan University, in 2011 and 2018, respectively. He currently works as a Postdoctoral Fellow in the Institute of Fundamental and Frontier Sciences of UESTC. Dr. Mu is working in the field of energy electrocatalysis. His main research interests include nitrogen reduction reaction, CO2 reduction reaction and spectroelectrochemistry.