PACS: 62.20.-x, 61.72.-y, 81.30.Kf, 81.40.-z, 89.20.Bb, 61.46.-w, 61.48.+e, 68.43.-h, 89.30.-g, 61.72.Lk, 61.72.Ss, 64.75.+g, 66.30.Jt