[1] Beijing Univ Technol, Coll Appl Sci, Beijing 100124, Peoples R China
[2] Univ S Florida, Dept Phys, Tampa, FL 33612 USA
[3] Natl Univ Ireland, Dept Comp Sci, Maynooth, Kildare, Ireland
[4] Natl Univ Ireland, Callan Inst, Maynooth, Kildare, Ireland
[5] Univ Coll Dublin, Commun & Optoelect Res Ctr, Dublin 4, Ireland
[6] Univ Coll Dublin, Sci Fdn Ireland SFI Strateg Res Cluster Solar Ene, Dublin 4, Ireland
[7] Univ Coll Dublin, Coll Engn Math & Phys Sci, Sch Elect Elect & Mech Engn, Dublin 4, Ireland