CC BY
7
https://doi.org/10.29013/ESR-21-7.8-41-43
Rasulov Voxob Rustamovich, associate professor of Fergana State University Rasulov Rustam Yavkachovich, professor of Fergana State University Mamatova Makhliyo Adkhamovna, doctoral student of Fergana State University Isomaddinova Umida Mamirjonovna, teacher of the Kokand State Pedagogical Institute Kodirov Nurillo Ubaydullo ogli, doctoral student of Fergana State University
INTERBAND SINGLE-PHOTON ABSORPTION OF POLARIZED LIGHT IN CRYSTALS WITH ALLOWANCE FOR THE EFFECT OF COHERENT SATURATION. 2-PART
Abstract. The spectral-temperature dependence of the coefficient of single-photon absorption of light in crystals of tetrahedral symmetry, due to optical transitions occurring from the spin-orbit splitting zone to the conduction band, is calculated. In this case, the contribution of the coherent saturation effect to the single-photon light absorption coefficient is taken into account.
Keywords: nonlinear light absorption, semiconductor, valence band, conduction band, direct optical transitions, interband light absorption.
In the first part of this work, it is indicated that the nonlinear absorption of light in a semiconductor with a degenerate valence band, which is due to direct optical transitions between the subbands of heavy and light holes and depends on the state of radiation polarization, was studied in [1-9]. In these papers, it is assumed that the nonlinearity in the intensity dependence of the single-photon absorption coefficient arises due to resonant absorption saturation.
We note here that the question of the spectral-temperature dependence of the single-photon absorption coefficient of light in the frequency range
w1 ^ f ((
hœ > Eg + ASO, when optical transitions from the spin-orbit splitting zone to the conduction band, where ha is the photon energy, Eg is the band gap, and is ASO the spin-orbit splitting energy, has remained open. Therefore, we further consider one-photon absorption of light between the spin-orbital splitting zone and the conduction band (at Eg +À50 < h®).
Then the spectral-temperature dependence of the single-photon light absorption coefficient due to optical transitions between the spin-orbital splitting zone and the conduction band is determined as
K
(i)
c ,SO
cfrn,, 3'
e +12 )(( - f) ^
or
K(i) =-
1 o1 ft2
1 6 PcV jU(c'SOk(lffl)f
3 chn h
soJso№
2m„
1-exp
+ Eg + ASO -
h2k
2m
- hœ
SO J
kT
f E
x -1 - SO
E
V g j j
(1)
Section 4. Physics
where ^
(c,SO) _ mcmSO
m„ + m
is the reduced effective
SO
mass, eo=J is the wave vector
(c, SO )
vc, SO
h2
of current carriers,
fso, klS> = exp 1 n(c'SO)
El
kBT_
■ exp
kBT mSO
Eg - ESO )
(2)
is the distribution function of current carriers in the spin-orbit splitting zone involved in optical transitions between the spin-orbit splitting zone and the conduction band.
The Fermi energy for current carriers located in the zone of spin-orbital splitting is determined by the formula for the concentration of current carriers, i.e.
pso=m fsaik 2dk=
= exp
F - A
F SO
kT
m exp
i
kT
v 2mc j
k dk.
(3)
Where do we get
exp
r E ^ F
kT
1 f kT
-3/2
m.
-3/2
Pso exP
A
(4)
SO
kT
2V2nh\
On (fig. 1) shows the spectral-temperature dependence of the coefficient of single-photon absorption of polarized light, due to optical transitions between the spin-orbital splitting subband and the conduction band in InSb without taking into account (a) and taking into account (b) the temperature dependence of the band gap and their ratio (c), where not the contribution of the coherent saturation effect to the single-photon light absorption coefficient is taken into account. The red line marks the intersection of the spectral and temperature dependences ofthe single-photon absorption coefficient ofpolar-ized light, shown in (Figs. 1 a and b). From (fig. 10) shows that in the spectral - temperature dependence ofthe single-photon absorption coefficient ofpolar-ized light, a maximum is observed.
References:
1. Ivchenko E. L. Two-photon absorption and optical orientation of free carriers in cubic crystals // Semiconductors.- Vol. 14.- Issue 12. 1972.- P. 3489-3485. (in Russian).
2. Rasulov R. Ya. Polarization optical and photovoltaic effects in semiconductors with linear and nonlinear absorption of light. Dissertation for thesis. of doctor's degree phys.-math. sciences.- St. Petersburg. 1993.- 206 p. (in Russian).
3. Ganichev S. D., Ivchenko E. L., Rasulov R. Ya., Yaroshetskii I. D. and Averbukh B. Ya. Linear and circular dichroism of drag current due to nonlinear inter subband absorption of light in p-type Ge//Phys. Solidi State.- V. 35.- No. 1. 1983.- P. 104-108.
4. Parshin D. A., Shabaev A. R. Theory of nonlinear absorption of infrared radiation in semiconductors with degenerate bands // ZhETF.- Moscow,- T.92.- Issue 4. 1987.- P. 1471-1484. (in Russian).
5. Rasulov V. R. Rasulov R. Ya., Eshboltaev I. Linearly and circular dichroism in a semiconductor with a complex valence band with allowance for four-photon absorption of light // Physics of the Solid State.-Springer,- Vol. 59.- No. 3. 2017.- P. 463-468.
6. Rasulov R. Ya., Khoshimov G. Kh., Kholitdinov Kh. / Linear-circular dichroism of the nonlinear absorption of light in n-GaP // Semiconductors.- T. 30.- No. 30.- No. 2. 1996.- P. 274-277. (in Russian).
7. Rasulov R. Ya. Drag effect at three-photon absorption of light in semiconductors of the Ge type // Semiconductors.- T. 22.- No. 11. 1988.- P. 2077-2080. (in Russian).
8. Rasulov R. Ya. Linear circular dichroism in multiphoton interband absorption in semiconductors // Semiconductors.- T. 35.- No. 6. 1993.- P. 1674-1678. (in Russian).
9. Rasulov R. Ya., Rasulov V. R., Eshboltaev I. The theory of the four photons of polarized radiation in a semiconductor with complex band structure // American Scientific journal.- New York,- No. 2. 2016.-P. 93-96.
