Jing Guo, a PhD student in Prof. Ying Jiang’s group of International Center for Quantum Materials, School of Physics, Peking University, won the first prize of the nc-AFM 2015 poster competition. The 18th International Conference on non-contact Atomic Force Microscopy (nc-AFM) was held from September 7 to September 11 in Cassis, France. The conference was initiated in Japan since 1988 and was held every year at many different countries, such as, Switzerland, Germany, USA, Canada et al. It covers experimental, theoretical and instrumental contributions by means of the different dynamic operation modes used in nc-AFM. Particular emphasis is placed on high resolution imaging, nanoscale manipulation, and force spectroscopy applications used for all kinds of applications in nanoscience. Jing Guo presented the work of “Submolecular-resolution imaging of the interfacial water with combined STM and NC-AFM” in the poster exhibition, which attracted wide attentions and was recognized as the most outstanding achievement out of more than 100 posters by the jurors of the conference.

About the poster: Water/solid interfaces are vital to our daily lives and resolving the internal structure, that is, the O–H directionality, of water molecules adsorbed on solid surfaces has been one of the key issues of water science yet it remains challenging. Here, we demonstrate unprecedented submolecular imaging of water on a Au-supported insulating NaCl(001) film and also show the possibility of discerning the orientation of water monomers and the H-bond directionality of water tetramers with STM. On the other hand, noncontact atomic force microscopy (nc-AFM) has recently shown the ability to identify the chemical structures of single molecules , which are complementary to the orbital information obtained with STM. Herein, using a Cl-terminated tip of nc-AFM, we are able to image the orbital and chemical structure of water tetramer and monomer simultaneously by tuning the tip height and the AFM sensor amplitude. Our results refresh the understanding of imaging mechanism with q-plus nc-AFM technique.