Selective methods formation of nanoparticles chalcogenide semiconductors

1
Selective methods formation of nanoparticles
chalcogenide semiconductors

• 14 January 2006

2
MUSTAFA B.MURADOV Baku State University NanoCentr
e E-mailmuradov_at_bsunanotechnology.com http//m
ustafa.sayt.ws/ Z.Khalilov 23, Baku, AZ1148,
AZERBAIJAN
3
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

4
Selective methods of growth

• Allow to operate the sizes of particles at level
  of monomolecular layer
• Atomic-layered epitaxy
• Chemical assembly
• Ion-layered chemisorptions

5
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

6
Process of growth

• Nanoparticles growth

7
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

8
Thermodynamics of prosses

• µCun µCus
• µCun -chemical potential of copper in
  nanoparticles, µCus - chemical potential of
  copper in solutions
• µµ0 kT lnC
• C- concentration of solutions, T-temperature,
  µ-chemical potentials, µ0-standard chemical
  potentials of particles, k- Boltzmann constant

9
The transmission spectra of samples
CdSgelatin/glass, dashed line after thermal
annealing (T90C, t30min), d30-200A, ?E0.7eV

10
The change of refractive indexstructure
CdSgelatin
11
Dependence of (ah?)2 from h? a)1 - 6, 2- 10,3-
15cycles b)1- 1, 2-4cycles of formation
?E0.45eV d11A


12
PERSPECTIVE OF PREPERATION NANOSTRUCTURE

• Selective growth process
• Sharp boundary between coreshell

Ion layered chemisorptions
Diffusion boundary between coreshell
CdS CuS transformation process
Ion-exchange
13
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) 457461
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.Bag
irova 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.
14
THE END

• THANKS FOR YOUR ATTENTION