
31Synthesis and Characterization of Quantum Dots
1.5
1.0
0.5
0.0
400 800
As-synthesized PbS NCs
Ambient storage 6 days
(a)
Ambient storage 3 days
1200
Wavelength (nm)
1600
2.0
1.5
1.0
0.5
0.0
400 800
As-synthesized PbS NCs
Ambient storage 6 days
Ambient storage 3 days
1200
Wavelength (nm)
Absorption (a.u.)
1600
FIGURE 2.13
(See color insert.) Comparison of oxidation characteristics of large (a, c) and small (b, d) PbS NCs. Absorption
change of (a) large PbS NCs and (b) small PbS NCs stored in octane solution in ambient for 0 day (black), 3days
(red), and 6 days (cyan); XPS S 2p spectra of as-fabricated lm (black), lm annealed in air at ...