3.4. SPECTROSCOPY
63
CdSe colloidal NCs
a = 1.2 nrn
J
I
I
I
I
I
I
I
I .8
2.0
2.2
2.4
2.6
2.8
3.0
Photon Energy (eV)
Figure 3.27. Room-temperature optical absorption spectra for CdSe colloidal nanocrystals
(NCs) with mean radii in the range from 1.2 to 4.1 nm. [From V. I. Klimov, in Nalwa (2000),
Vol. 4, Chapter 7, p. 464.1
irradiated with ultraviolet light (UPS) or X rays (XPS) can emit electrons called
photoelectrons from atomic energy levels with a kinetic energy equal to the
difference between the photon energy h V p h and the ionization energy Eion, which
is the energy required to completely remove an electron from an atomic energy level
KE h V p h - Eion
(3.11)
63
CdSe colloidal NCs
a = 1.2 nrn
J
I
I
I
I
I
I
I
I .8
2.0
2.2
2.4
2.6
2.8
3.0
Photon Energy (eV)
Figure 3.27. Room-temperature optical absorption spectra for CdSe colloidal nanocrystals
(NCs) with mean radii in the range from 1.2 to 4.1 nm. [From V. I. Klimov, in Nalwa (2000),
Vol. 4, Chapter 7, p. 464.1
irradiated with ultraviolet light (UPS) or X rays (XPS) can emit electrons called
photoelectrons from atomic energy levels with a kinetic energy equal to the
difference between the photon energy h V p h and the ionization energy Eion, which
is the energy required to completely remove an electron from an atomic energy level
KE h V p h - Eion
(3.11)