One major interest of our lab is to control the morphology and the growth mode of ultrathin film covered systems. One example is our work on the reversible phase transitions between faceted and planar forms of adsorbate covered W(111) surfaces, which nicely demonstrates the rich possibility in adsorbate induced self-organization of the surface. In particular, the Pd induced faceting of W(111) surface has recently been utilized by others to reproducibly prepare well defined atomically sharp tips, which is crucial for scanning tunneling microscopy with atomic resolution. Our current goal is to seek either ways to produce periodic arrays of facets, or ways to create facets that can form sharper tips.
       More recently we have been studying the "interfactant" assisted epitaxy. With our own temperature programmed Auger instrumentation, we found the strong tendency of potassium to agglomerate on W(111) can be suppressed by introducing a submonolayer of Ag at the interface. We propose that the Ag acts like an anti-reflection coating for the electronic states in the potassium film, and it is the "de-confinement" of the electronic states that makes the planar form the most stable one. The "interfactant assisted epitaxy" should be of practical value to the making of photocathode, which determines the quantum efficiency of a photomultiplier.
      Most recently, in collaboration with Prof. M. T. Lin of NTU, we have started an effort to try all various kinds of method to create surface superstructures with large unit cell. The eventual goal is to be able to grow magnetic nanostructures on these periodic templates.
      When this lab is first started, we had invested quite some effort on laser setup for nonlinear optical spectroscopy measurements. As a result, we are ready to take advantage of laser as structural manipulating tools. Currently, we have a pilot project studying laser induced nucleation of super saturated solution. We are also interested in the potential of using high power laser to manipulate the growth of nano-particles.