溶液扫描隧道显微镜的高稳定高分辨率成像研究

The Scanning Tunneling Microscope (STM) worked in solution, which is having played a very important role at molecular scale in solid-solution interface, is a type of STM breaking its highly static working environment, and thus has a wider application. However, the common solution STM is difficult to obtain high stability and resolution compared with the highly static STM, leading to its limited range of application, because the common STM worked in solution is just the simple transplantation from highly static STM, which does not have systematic analysis and improvement designed to the harsh environment. . This project taking the high stability and image clarity of solution STM as a specialized scientific topics, aims at researching and solving the problem of highly stable atomic resolution imaging of STM in solution environment without a soundproofing. We intend to use the following way: (1) For improving the rigidity and stability of the scanning structure, we utilize the piezo motor with double stacks propelling the subminiature scanning head, which is fully symmetrical and high rigid, to detect the tunneling current. (2) We use the homemade ultra-sensitive pre-amplifier and two-way adjustable bias circuit to amplify the weak tunneling current with low interference, and the homemade voltage amplifier circuit with features of low noise and high precise to contorl the elongation and constriction of the motor and scanning tube. (3) We write the special control procedures based on Labview for the highly stable solution STM, which has complete functionality and high control accuracy.

溶液扫描隧道显微镜（STM）是突破STM高静态环境的一个典型代表，相比于传统的高静态环境具有更为广泛的应用空间，在分子尺度的固-液界面研究中取得了不少成果。但通常的溶液STM只是对高静态STM在溶液中的简单移植，没有针对恶劣环境将STM进行系统的分析和改进，因此难以达到高静态STM的稳定性和分辨率，对重要物性的揭示存在很大的限制。. 本项目将溶液STM的成像清晰度和稳定性作为专门的科学课题进行探索，在现有工作基础上研究并解决无隔音溶液STM的高稳定原子分辨率成像问题。拟采用（1）双分支堆栈压电马达推进高刚性全对称微型扫描头进行隧道电流探测，有效提升扫描回路的刚性和稳定性。（2）自制超灵敏前级放大电路和可调双向偏置电路为微弱信号的低干扰放大提供保障，自制低噪音高压放大电路控制马达和扫描管的精确伸长。（3）基于Labview编写高稳定溶液STM的专用控制程序，保证功能完整性和控制精确度。

本项目将溶液STM的成像清晰度和稳定性作为专门的科学课题进行探索，在原有工作基础上研究并解决无隔音溶液STM的高稳定原子分辨率成像问题。采用了（1）高刚性压电马达推进高刚性全对称微型扫描头进行隧道电流探测，有效提升扫描回路的刚性和稳定性。（2）自制超灵敏前级放大电路为微弱信号的低干扰放大提供保障，自制低噪音高压放大电路控制马达和扫描管的精确伸长。（3）自主搭建控制系统并基于Labview编写高稳定溶液STM的专用控制程序，保证功能完整性和控制精确度。. 本项目仪器已经全部搭建完成并可常态化使用，并作为仪器平台与南京邮电大学建立起紧密的合作研究关系，接下来会进一步增加材料生长、化学反应、生物、表面物理等领域的合作交流。另外在本项目支持下，项目负责人共发表一作者SCI论文4篇，圆满完成本项目研究目标。