zhenli-nanoresearch-14 chen-APL-2014 jing-pccp-2014 SherminNanoResearch2013 Moh_NL_2013 shun-wenchangNanoResearch2013 Chen_APL_2012 Shun-wen_IEEE_TN_2013 Zuwei_NL_2011 Chen_APL_2012 Moh_NL_2012 ChiaChi_NL_2012 Rohan_PRB_2012