Heterovalent Cation Substitutional and Interstitial Doping in Semiconductor Sensitizers for Quantum Dot Cosensitized Solar Cell

Figure 4

XPS of (a) S 2s peaks, (b) Pb 4f peaks, (c) Bi 4f peaks, and (d) Ag 3d peaks for PbS, Bi-doped-PbS, and Ag-doped-PbS QDs adsorbed on mesoporous TiO₂ surface.

(a)

(b)

(c)

(d)