Synthesis of and Charge Transfer Dynamics in Type II Nanorod Heterostructures

该奖项由大分子，超分子和纳米化学（MSN）计划支持伊利诺伊大学厄巴纳-香槟分校的Moonsub Shim教授的工作，以开发有效分离和引导光生电荷的多组分纳米级半导体材料。涉及从光子产生的电荷的这两个过程是光子学、光催化剂、光电探测器和涉及光捕获/检测的许多其他设备中的第一步和最重要的步骤。通过改变这些多组分纳米级半导体的尺寸、组成和结构/拓扑，这项研究将允许利用量子力学和机械应变效应来控制光生电荷的操纵方式。电荷分离过程将通过瞬态光谱技术进行检查，使用亚皮秒激光脉冲来跟踪光子产生的电荷载流子的空间分布和能量耗散。这些研究扩展到嵌入光学透明和导电介质（如导电/半导体聚合物和氧化物）的多组分纳米材料，将为如何有效地提取光生电荷以做有用的电学工作提供新的见解。该计划的成功将导致新材料和器件概念用于下一代光化学。合理设计和合成具有精确尺寸、组成和拓扑结构的多组分半导体材料的能力，沿着对这些材料中的光致电荷分离过程的理解，通常将有利于开发各种各样的太阳能转换和光电应用。该计划还将为新兴跨学科领域的研究生和本科生提供充足的教育和培训机会。参与该项目的学生将在伊利诺伊大学和阿贡国家实验室的最先进设施上接受培训。该项目还将产生可直接用于促进课堂教学和公众对纳米科学和清洁能源技术的兴趣的信息和演示材料。

This award by the Macromolecular, Supramolecular, and Nanochemistry (MSN) program supports work by Professor Moonsub Shim at the University of Illinois at Urbana-Champaign to develop multi-component nanoscale semiconductor materials that are efficient at separating and directing photogenerated charges. These two processes involving charges generated from photons are the first and the most important steps in photovoltaics, photocatalysts, photodetectors and many other devices involving light harvesting/detection. By varying size, composition and structure/topology in these multi-component nanoscale semiconductors, this research will allow exploitation of quantum mechanical and mechanical strain effects to control how photogenerated charges are manipulated. Charge separation processes will be examined by transient spectroscopic techniques using sub-picosecond laser pulses to follow spatial distribution and energy dissipation of charge carriers created by photons. These studies extended to multi-component nanomaterials embedded in optically transparent and electrically conducting media such as conducting/semiconducting polymers and oxides will provide new insights on how photogenerated charges may be efficiently extracted to do useful electrical work.The success of this program will lead to new materials and device concepts useful for next-generation photovoltaics. The ability to rationally design and to synthesize multi-component semiconducting materials with precise size, composition and topology along with the understanding of photoinduced charge separation processes in these materials will in general be beneficial for developing a wide variety of solar energy conversion and optoelectronic applications. The program will also provide ample educational and training opportunities for graduate and undergraduate students in emerging interdisciplinary fields. Students involved in this project will be trained on state-of-the-art facilities both at the University of Illinois and at Argonne National Laboratory. This project will also generate information and demonstration materials that can be directly used to promote both classroom teaching and general public's interest in nanoscience and clean energy technologies.