Strongly Bound Frenkel Excitons on TiO2 Nanoparticles: An Evolutionary and DFT Approach
Table 2
Parameters calculated with the PBE/PAW method for the Wannier exciton model of anatase and rutile using the high-frequency () and static dielectric constants ().
Phase
Method
a
(meV)a
a x (Å)
Anatase
0.51
0.48
0.44
242.6
13.77
5.81
38.7
10
PBE
0.41
0.35
0.36
137.6
1.99
4.73
47.6
13
PBEsol
0.37
0.32
0.32
125.7
2.57
4.28
52.5
14
Experimental
180b
Rutile
0.91
0.91
1.16
313.8
8.10
0.55
77.3
26
PBE
0.85
0.76
1.07
187.1
121.6
0.51
83.4
28
PBEsol
0.78
1.0
1.00
169.5
0.06
0.47
89.6
30
Experimental
4c
aReduced effective mass () and calculated using different dielectric constants. bExciton binding energy for direct transition from Ref. [13]. cFrom Ref. [11].