Transcript Selective methods formation of nanoparticles chalcogenide

Selective methods
formation of nanoparticles
chalcogenide
semiconductors
14 January 2006
MUSTAFA B.MURADOV
Baku State University
NanoCentre
E-mail:[email protected]
http://mustafa.sayt.ws/
Z.Khalilov 23, Baku, AZ1148, AZERBAIJAN
NANOPARTICLES
New physical and chemical properties
Thermodynamic peculiarities
Opportunities of creation essentially new
materials and devices
Opportunity of controlling of physical and
chemical properties of materials
-By changing of nanoparticle size
-By changing of parameters core/shell structure
Selective methods of growth
Allow to operate the sizes of particles at
level of monomolecular layer
• Atomic-layered epitaxy
• Chemical assembly
• Ion-layered chemisorptions
Ion-layered chemisorptions
(One cycle of formation)
• Adsorptions of cations on surface (volume)
of substrate
• Washing residue of electrolytes with the
solvent
• Adsorptions of anions on surface (volume)
of substrate
• Washing residue of electrolytes with the
solvent
Process of growth
2
• Nanoparticles growth
1
Fig.1а
1-glass substrate
2-gelatin film
1
Na2S
2
H2O
H2O
3
CuSO4
4
H2O
H2O
5
Features of growth
• Opportunity of controlling structure and
stochiometric composition with the help of
changing thermodynamic parameters of
system
• Growth of structures in conditions of
local thermodynamic equilibrium
Thermodynamics of prosses
• µ =µ
• µ -chemical potential of copper in
Cun
Cus
Cun
nanoparticles, µ - chemical potential of copper
in solutions
• µ=µ +kT lnC
C- concentration of solutions, T-temperature, µchemical potentials, µ -standard chemical
potentials of particles, k- Boltzmann constant
Cus
0
0
The transmission spectra of samples CdS:gelatin/glass, dashed line
after thermal annealing (T=90C, t=30min), d=30-200A, ∆E=0.7eV
E 
2
2
 
*
2
2m d
The change of refractive index
structure CdS:gelatin
Dependence of (αhν)2 from hν; a)1
- 6, 2- 10,3- 15cycles; b)1- 1, 24cycles of formation; ∆E=0.45eV;
d≥11A
(h)
2
PERSPECTIVE OF PREPERATION NANOSTRUCTURE
CdS
CuS
•Selective growth process
•Sharp boundary between
core&shell
Ion layered chemisorptions
Diffusion boundary between
core&shell
CdS
CuS transformation
process
Ion-exchange
REFERENCE
1. A.M.Kutepov, V.N.Maslov, V.S.Pervov, M.B.Muradov, Fractal
growth of cadmium sulfide films during ionic-layered
chemisorption,Doklady Akademii Nauk SSSR, 1989 v.304, №4,
p.1900-1903(in Russian)
2. J. Puiso, S. Tamulevicius , G. Laukaitis , S. Lindroos , M. Leskela ,
V. Snitka Growth of PbS thin films on silicon substrate by SILAR
technique Thin Solid Films 403 –404 (2002) 457–461
3. M.B. Muradov, A.A. Agasiyev, Formation of cadmium sulfide
particles in te volume of polimeric matrix., Pisma v Zhurnal
Technicheskoy Fiziki 1991,v.17, issue.13, p.54-57(in Russian).
4.M.B.Muradov, V.L.Smirnov, V.A.Karavanskii Patent USSR
N1448914, 1986;.
5. M.B.Muradov, G.M.Eyvazova,N.H.Darvishov,S.E.Bagirova Some
optical properties of nanoparticles copper sulphide, formed in
volume of a polymeric matrix, Transaction NAS Azerbaijan, ser.
Physical-mathematical and technical science, 2004,№5.
THE END
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