? ? Ultrahigh-density data storage has received much attention?in recent years because of its technological importance, and?substantial progress has been made lately.[1±6] Haridas and?coworkers have suggested three-dimensional high-density?data storage based on two photos. Chou et al. used nanoimprinting?lithography for high-density data storage.[2,3] Scanning?probe microscopy (SPM) has a potential application in?high-density data storage due to its ability to make local electric?fields from the tip on a nanometer scale.[7±14] Recording at?the nanometer scale has been demonstrated by SPM on various?materials. Among them, organic molecules have received?much attention because of their controllable molecular structures?and corresponding properties.[15±26,28] By changing?molecular structure, it is possible to optimize recording on?organic materials. Furthermore, the size of the recorded mark?can possibly be at a molecular scale. In the past, we have?reported molecular recording on a few organic materials up to?a data density of about 1013 bits/cm2.[5±7,17] To decrease the?size of the recorded marks, correspondingly increase their?density, and furthermore understand the recording mechanism,we have designed and synthesized different molecules.In this communication, we report molecular recording on an?organic p-nitrobenzonitrile (PNBN) thin film by STM under?ambient conditions, which shows the smallest mark size?among all the organic thin films previously studied. A possible
recording mechanism is discussed.
DX Shi,YL Song,DB Zhu,HX Zhang,SS Xie,SJ Pang.