Films minces à base de Si nanostructuré pour des cellules ...

tel-00916300, version 1 - 10 Dec 2013
4.40 Comparing the PL spectra obtained after STA and 4.75h-FG annealing
processes in 50 and 100 patterned SRSO/SRSN MLs. . . . . . . . 126
4.41 PL spectra obtained from 50(3.5/5) ML after STA + FG annealing. 127
4.42 Investigating the PL spectra obtained from 50(3.5/5) SRSO/SRSN
ML after FG+STA. (The PL spectra obtained after STA (1min-1000°C
N 2 ) from 50 and 100 patterned MLs are also given in dotted lines for
comparison). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
4.43 PL spectra from 50(3.5/3.5) SRSO/SRSN, SRSO/SiO 2 and SRSN/SiO 2
MLs after STA and CA treatments. . . . . . . . . . . . . . . . . . . 129
4.44 PL spectra obtained from FG annealed 50(3.5/5) SRSN/SiO 2 . . . . . 130
4.45 Surface microstructure of 50(3.5/5) ML after N 2 , FG and N 2 +FG
annealing as observed by optical microscope. . . . . . . . . . . . . . 132
4.46 I-V curve of STA SRSO/SRSN versus CA SRSO/SiO 2 . . . . . . . . . 135
5.1 Schematic representation of external and internal components of our
thin lm samples under investigation. in TE mode. θ inc = 45 o and
θ collect = ±23 o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
5.2 The variation of complex refractive index (ñ = n(λ)−ik(λ)) of a thin
lm, as a function of wavelength. . . . . . . . . . . . . . . . . . . . . 141
5.3 Pump intensity prole with regard to its angle of incidence on the
thin lm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
5.4 Inuence of total lm thickness on the pump prole. . . . . . . . . . 142
5.5 Pump prole versus real part of thin lm refractive index (n 2 ). . . . 143
5.6 Pump prole versus imaginary part of thin lm refractive index (k 2 ). 144
5.7 An illustration of the pump prole variation in a thin lm of thickness
d(nm) with distribution of emitters in monolayer conguration. . . . 144
5.8 An illustration of the pump prole variation in a thin lm of thickness
d(nm) with distribution of emitters in multilayer congurations. . . . 145
5.9 Schematic representation of the various components of the incident
wave and the wave from a single emitter placed at a distance x e in
the thin lm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
5.10 Four level system for modeling absorption and emission. . . . . . . . 148
5.11 Distribution of emitters with depth in a lm of 1000 nm thickness.
Left axis: Number of emitters in a small thickness dx and Right
axis: volumic concentration per m 3 . (Simulated with Incident pump
intensity: 10 5 W/m 2 ). . . . . . . . . . . . . . . . . . . . . . . . . . . 149
5.12 The shapes of k(λ) and k (λ, x). Lorentzian t of the k(λ) obtained
through experiments, gives the shape of k(λ, x). . . . . . . . . . . . . 151
xi