The document summarizes research on producing Cu2ZnSnS4 (CZTS) thin films for solar cell applications using spray pyrolysis deposition. Key points: 1) CZTS thin films were successfully deposited using a simple and inexpensive spray pyrolysis technique involving spraying a precursor solution containing copper, zinc, tin, and sulfur compounds onto a heated substrate. 2) Characterization of the films showed that increasing thickness improved crystallinity, grain size, optical absorption in the desired 1.6-1.67eV range, and electrical conductivity. 3) The research demonstrated the spray pyrolysis technique can effectively produce CZTS thin films for solar cells in a single-step process without vacuums or

1. Cu 2 ZnSnS 4 (CZTS) Thin Films for
Solar Cell Application
Dr. Ramesh J. Deokate
Vidya Pratishthan’s
Arts, Science and Commerce College,
Baramati
VPA SC
MS-413 133.

2. Outline of Presentation
Introduction of Cu2ZnSnS4(CZTS)
 Synthesis of Cu2ZnSnS4 Thin films
 Characterization techniques:
 X-ray diffraction (XRD )
Scanning Electron Microscopy (SEM)
Theromoemf power (TEP)
Resistivity measurement
 Contact angle and Band gap study
Conclusions
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3. Properties of Cu2ZnSnS4 (CZTS)
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4. Methodology
Advantages of SPT


Neither requires high quality targets
and/or substrates nor it requires
vacuum at any stage, which is a great
advantage if the technique is to be
scaled up for industrial applications.

The deposition rate and the thickness of
the films can be easily controlled over a
wide range by changing the spray
parameters.

Operating at moderate temperatures
(373-773 K), spray pyrolysis can
produce films on less robust materials.

It can be used to make layered films and
films having composition gradients
throughout the thickness.

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Inexpensive, simple and convenient for
large area deposition.
This method provide one step synthesis
without no impurities.
Schematic representation of spray pyrolysis deposition apparatus

5. Preparation of Cu2ZnSnS4 films by Spray
pyrolysis technique
Chemicals used and preparative
parameters
Precursor solution
(Cd(CH3COO)2.2H2O) (0.025)
(Zn(CH3COO)2
SnCl4
4SC(NH2)2
Total quantity
80 ml
Deposition temp.
623 K
Deposition period
20 min.
Substrate
(0.025)
(0.025)
(0.2)
Glass
Reaction mechanism
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2Cu(CH33COO)+ Zn(CH33COO)2+SnCl4+
2Cu(CH COO) + Zn(CH COO)2+ SnCl4+
8H22O+4SC(NH22)2→ Cu22ZnSnS4+4CO22↑+
8H O+ 4SC(NH )2 → Cu ZnSnS4+ 4CO ↑+
4CH33COOH↑+4NH44Cl↑+4NH3↑
4CH COOH↑+ 4NH Cl↑+4NH3↑

6. Film thickness measurements
Variation of Cu2ZnSnS4 film thickness for different solution quantity.
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7. X-Ray diffraction (XRD) studies
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8. Scanning Electron Micrograph (SEM)
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9. Wettability Study
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10. Optical study and Electrical Resistivity
Increasing film thickness
Increasing film thickness
the band gap energy
the band gap energy
increases from 1.59 to 1.67
increases from 1.59 to 1.67
eV.
eV.
4.0
log ρ (Ω−cm)
3.6
The resistivity decreases with
The resistivity decreases with
increase in temperature which
increase in temperature which
is the indication of typical
is the indication of typical
244 nm
375 nm
568 nm
754 nm
semiconductor characteristic..
semiconductor characteristic
3.2
2.8
2.4
2.0
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1.0
1.5
2.0
2.5
3.0
-1
1000/T (K )
3.5
4.0

11. Summary and conclusions
 The CZTS thin films have been successfully deposited by a simple
and inexpensive spray pyrolysis technique.
 The thickness of CZTS films affects structural, optical and electrical
properties.
 The crystallinity and the grain size increased with film thickness.
Optical absorption study revealed indirect direct transition with
band gap energy in the range 1.6 to 1.67 eV, depending on film
thickness.
 The electrical conductivity and contact angle were enhanced with
the film thickness.
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12. Acknowledgement
Authors are grateful to University of Pune
(UoP) for financial support through the BCUD
scheme no. 36-207/2012-14 (SR).
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13. Thank You
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