The ZnS thin film is made by a chemical bath method. the structure and optical nature noted from XRD studies and UV studies

2. Name: Krishna Prasad
Course code: 630
Exam code: 630144404
Centre code:140
Candidate code: 63017140005
Sub. Code: PH201

3. STRUCTURAL &
OPTICAL
STUDIES OF
CHEMICALLY
DEPOSITED ZnS
THIN FILMSAIM: To study the
structural and
optical characters
of chemically
deposited ZnS thin
film.
MATERIAL STUDY:
Explanation to the
characteristic features of
ZnS. CHARACTERISATION TECHNIQUE:
Explanation about the methods used for
thin film preparation (Mainly CBD).
EXPERIMENTAL SETUP: The
experimental setup for
chemical bath deposited ZnS
thin film.
RESULT: The structural and
optical characters of ZnS
thin film by using XRD and
UV methods.

4. A I M
AIMS

5. Zinc sulphide is a
Ⅱ-Ⅵ
semiconductor is a
promising opto-
electronic device
with bandgap 3.72-
3.77 ev.
Zinc sulphide exist in
mainly 2 forms one is
cubic (zinc blend) other is
hexagonal (wurtzite).
The cubic is stable at room
temperature while hexagonal
is low dense and stable at high
temperature.
Global equation on the preparation of zinc sulphide
is given below
Zn(NH3)4
2++ SC(NH2)2 + 2OH– ZnS +
4NH3 + CH2N2 + 2H2O. It may allow us to
easily control
the growth factors
such as film
thickness, deposition
rate and quality of
crystallites by
varying the solution
pH, temperature and
bath concentration.
MATERIAL STUDY

6. PROPERTIES OF THIN FILM
• The method of deposition
• The substrate material
• The substrate / bath temperature
• The rate of deposition
• The background pressures
• Precursor concentration
A
B

7. Factor
e
re
s

8. TYP
E1
ION BY ION
PROCESS
This is the simple
one in which the
ions condense at
the reacting
surface to form
the film.
TYPE
2
CLUSTER BY
CLUSTER
PROCESS
In this case colloidal
particles are formed
in the solution as a
result of
homogeneous
reaction.
TYPE
3
MIXED
PROCES
S
Generally, both
the above said
processes may
interact with each
other leading to
the films in which
the colloidal
material is
included in the
growing films.

9. ZnS solution preparation:
Global equation on the preparation of zinc sulphide is given below
Zn(NH3)4
2++ SC(NH2)2 + 2OH– ZnS +4NH3 + CH2N2 + 2H2O. The
reagents are zinc acetate,thiurea, amonia for the preparation of .1M solution.
Thin film preparation:
The ZnS solution was taken in a beaker and the glass plates with corrected measurements
will be dipped in it for 3hours. Then, the plates were carefully placed in the furans and its
temperature will be set to 3000c. after achieving the temperature it will be cooled down
naturally. After 4 hours we open the furans and the coated glass plates kept safely for further
studies.
Experimental set up:
The experimental set up consist of three main parts (1)
Magnetic stirrer with thermostat, (2) chemical bath, (3)
substrate holder
Further studies:
we studied the optical and structural characters
using the characterisation techniques called X-
ray diffraction (XRD), and UV optical
characterisation.
1
2
4
3
Solution preparation &
experimental set up

10. X-ray diffraction is the
most widely used
characterization
technique for the
determination of
crystallographic
structure of the films.
It gives the information
regarding the lattice
parameters, crystal
structure, orientation,
defects, crystallite size
and stress if any
present in the films.
Zinc sulphide exist in
mainly 2sample according
to Bragg’s law.
Optical spectroscopy is a
powerful method for
understanding the properties of
semiconductor materials and
devices
For excitation, different laser sources from UV
(325 nm), This allows measuring the
photoluminescence and excitation spectra of a large
number of semiconductors.
In order to determine
the optical properties
such as optical
absorption coefficient
and energy band gap,
the optical studies
were carried out using
optical
spectrophotometer.
Further studies

11. RESULTS
A I M
A I M

12. RESULTS
XRD spectrum of ZnS Thin film
Angle d Value FWHM Size
28.392 3.1409 0.144 59.24

13. RESULTS
UV-Vis absorbance

14. Thank you