Creating, characterizing and probing new type of 2D novel systems
Shu-Jung Tang1*
1Physics, National Tsing Hua University, Hsinchu, Taiwan
* presenting author:Shu-Jung Tang, email:sjtang@phys.nthu.edu.tw
In this talk, I would like to give an introduction of my current researches on 2D systems related to thin films and interfaces. There are two main categories. One is on metal thin films and another is on organic thin films. As for the former, I will introduce the recent results of PbAu alloys grown on Ge(111) [1], which unfolds a large Rashba effect, yielding two Dirac cones at and two giant Rashba splittings at . Among these effects, the bottom cone at and the top Rashba splitting at exhibit great Rashba parameters, 4.45 and 6.26 eVĂ…, respectively. As for the latter, I will depict a novel model we built: uniform Ag thins films sandwiched by the top organic films, copper phthalocyanine (CuPc), and the bottom semiconductor substrate, Ge(111) [2], From this model, we found that quantum well states of Ag films can mediate the interaction between the top organic films and the bottom semiconductor substrate, inducing an interfacial gap state at organic-metal interface with its energy tuneable via the thickness of Ag thin films. This would provide a new method to engineer organic-based electronic devices. At last, I will briefly introduce my latest breakthrough in growing the 2D novel material of one atomic layer of Ge, Germanene.

References

1. Dirac cones induced by significantly enhanced giant Rashba splitting in a thin film of binary alloy, Wei-Chuan Chen,Tay-Rong Chang, Sung-Ting Tsai, Sh. Yamamoto, Je-Ming Kuo, Cheng-Maw Cheng, Ku-Ding Tsuei, Koichiro Yaji, Hsin Lin, H -T Jeng, Chung-Yu Mou, Iwao Matsuda, S.-J. Tang*, currently under review.

2. Tuning gap states at organic-metal interface by quantum size effects, Meng-Kai Lin, Yasuo Nakayama, Chin-Hung Chen, Chin-Yung Wang, Shin-ichi Machida, H.-T. Jeng, Tun-Wen Pi, Hisao Ishii, S.-J. Tang*, Nature Communications 4, 2925 (2013).



Keywords: thin films and interfaces, Rashba effect, interfacial gap state , Germanene