博士后学术沙龙第十期

文:唐莹 / 来源:微固学院 / 2017-04-19 / 点击量:575

  为搭建我校博士后之间的学术交流平台,促进学术水平提升,学校博士后管理办公室组织开展博士后学术沙龙活动。本次沙龙由我校博士后王宪思、罗强、伍芳分享其研究成果,诚挚邀请感兴趣的师生参加。

  一、时 间:2017年4月21日(周五)14:30

  二、地 点:清水河校区经管楼宾诺咖啡

  三、主办单位:电子科技大学博士后管理办公室

  四、承办单位:微电子与固体电子学院 电子科技大学博士后联谊会

  五、活动安排:

  报告一:

  (1)主题:Topologically Protected Unidirectional Edge Spin Waves and Beam Splitter

  (2)主讲人: 王宪思 微电子与固体电子学院博士后 

  (3)交流内容:

  Magnetic materials are highly correlated spin systems that do not respect the time-reversal symmetry. The low-energy excitations of magnetic materials are spin waves whose quanta are magnons. Like electronic materials that can be topologically nontrivial, a magnetic material can also be topologically nontrivial with topologically protected unidirectional edge states. These edge states should be superb channels of processing and manipulating spin waves because they are robust against perturbations and geometry changes, unlike the normal spin wave states that are very sensitive to the system changes and geometry. Therefore, the magnetic topological matter is of fundamental interest and technologically useful in magnonics. Here, we show that ferromagnetically interacting spins on a two-dimensional honeycomb lattice with nearest-neighbour interactions and governed by the Landau-Lifshitz-Gilbert equation, can be topologically nontrivial with gapped bulk spin waves and gapless edge spin waves. These edge spin waves are indeed very robust against defects under topological protection. Because of the unidirectional nature of these topologically protected edge spin waves, an interesting functional magnonic device called beam splitter can be made out of a domain wall in a strip. It is shown that an in-coming spin wave beam propagating along one edge towards a domain wall will be guided along the domain wall and split into two spin wave beams propagating in two opposite directions along the other edge. It is found that there are two branches of bound spin waves in the domain wall and their superpositions can result in different power division ratios depending on the strip width (domain wall length). Various types of devices are designed based on these findings.

  主讲人简介:

  Wang Xiansi received his bachelor degree in University of Science and Technology of China in 2010. He got his PhD degree in the Hong Kong University of Science and Technology in 2016. He currently works as a Postdoctoral Fellow in the School of Microelectronics and Solid-state Electronics of UESTC. Dr. Wang’s research interests include magnetism and spintronics. Specifically, he focuses on numerical and analytical analyses of Landau-Lifshitz-Gilbert equation, domain wall dynamics, and spin transport in multilayer structures.

  报告二:

  (1)主题:Efficient and Photostable Perovskite Solar Cells Employing Rationally Designed Charge Contacts

  (2)主讲人:罗强  微电子与固体电子学院博士后 

  (3)交流内容:

  Organic-inorganic lead halide perovskite solar cells are arising as strong candidates for next generation of renewable energy conversion devices due to their high efficiency, low material and fabrication cost, and scalable manufacture capability. With the continued development of the perovskite compositions and optimization of device interfaces, the maximum power conversion efficiency of single junction perovskite solar cells has been boosted to a certified 22.1% for small area device and close to 20% for 1 cm2 size device, approaching the efficiency of commercialized crystalline silicon and CIGS solar cells. While high efficiency has been demonstrated, stability and material cost are two dominate factors that determine the commercialization of perovskite solar cells. Simultaneously realizing the enhanced photostability and high efficiency, herein we demonstrate the rationally designed iron (III) oxide charge extracting materials and low-cost cross-stacked carbon nanotubes back contacts for efficient and photostable perovskite solar cells. Perovskite solar cells fabricated iron (III) oxide electrodes showed a promising power conversion efficiency of over 18% and excellent photostability. Moreover, we will report an inverted CH3NH3PbI3/NiO perovskite solar cell with cross-stacked carbon nanotube film cathode. Rigid and flexible perovskite devices based on carbon nanotube cathodes deliver promising conversion efficiencices of 14.3% and 10.5% respectively. Moreover, both rigid and flexible devices show excellent stability after long-term thermal stress or continuous light soaking. Our results indicate that the rationally designed iron (III) oxide and cross-stacked carbon nanotube are promising electrode materials for long-term device operation and pave the way toward realistic commercialization of perovskite solar cells.

  主讲人简介:

  Luo Qiang received his PhD degree in Tsinghua University in 2016. He currently works as a Postdoctoral research Fellow in the School of Microelectronics and Solid-state Electronics of UESTC. Dr. Luo’s research interests focus on inorganic charge contacts and light absorbers for photovoltaic application, including sensitized solar cells, perovskite solar cells etc.

  报告三:

  (1)主题:微流控技术简介及其应用

  (2)主讲人:伍芳  能源科学与工程学院博士后

  (3)交流内容:

  微流控(Microfluidics)是一门精确操控和处理微尺度流体的科学和技术,通常指利用尺寸范围为数十到数百微米的通道对微体积(一般为10-9到10-18 L)的流体进行精确地操控的技术,又被称作芯片实验室技术(Lab-on-a-chip)。微流控技术是一个由微电子学、工程学、物理学、化学、微加工、生物工程和技术等多学科的交叉领域,主要以分析化学和生物学为基础,利用微机电加工技术构建集成的微尺度管道网络,将包括采样、稀释、添加试剂、反应、分离、检测等过程的化学实验室的功能集成在载玻片大小的微芯片上,以实现对微量流体的精确控制和操作。微尺度下流体具有高的比表面积和高的传质性能,可大幅缩短样品处理时间,提高检测分辨率和灵敏度,同时减少样品消耗和降低成本。微流控技术的出现和发展为微尺度流体的精确操控和大规模应用提供了新的平台。因此,微流控技术吸引了广泛关注和重视,尤其在化学和生物医学领域发展迅速,譬如微反应、生物分析、“Point-of-care”诊断医学、分子分离、细胞分选、燃料电池、纳米颗粒的合成和结构功能材料的制备等,在微反应器、分析检测、药物控释、细胞研究、纳米颗粒合成和功能材料制备等领域具有巨大的应用潜力。

  主讲人简介:

  伍芳,2016年毕业于四川大学,获得博士学位;同年9月于电子科技大学能源学院高密度电源实验室从事博士后研究。博士期间从事利用微流控技术与层层自组装技术的生物医用功能高分子水凝胶的制备与性能研究,包括核壳结构微胶囊、有机无机复合微胶囊、凝胶微纤维等;博士后期间的研究内容为:基于层层自组装技术的纳米复合材料的制备及其电化学性能研究,包括碳包覆硅纳米复合颗粒、二氧化钛包覆归纳米复合颗粒等。


                 电子科技大学博士后管理办公室

                    2017年4月17日


编辑:林坤  / 审核:罗莎  / 发布者:一戈