[1] Trinity Coll Dublin, Ctr Res Adapt Nanostruct & Nanodevices CRANN, Dublin 2, Ireland
[2] Trinity Coll Dublin, Adv Mat & Bioengn Res Ctr AMBER, Dublin 2, Ireland
[3] Trinity Coll Dublin, Adv Microscopy Lab, Dublin 2, Ireland
[4] Trinity Coll Dublin, Sch Chem, Dublin D02, Ireland
[5] Indian Inst Technol Kharagpur, Mat Sci Ctr, Kharagpur 721302, India
[6] Trinity Coll Dublin, Dept Elect & Elect Engn, Dublin 2, Ireland
[7] Helmholtz Zentrum Berlin Mat & Energie, D-14109 Berlin, Germany