The effect of annealing on structural optical and photosensitive properties of electrodeposited cadmium selenide thin films

Journal of Science: Advanced Materials and Devices 2 (2017) 165e171

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Journal of Science: Advanced Materials and Devices
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Original Article

The effect of annealing on structural, optical and photosensitive
properties of electrodeposited cadmium selenide thin films
Somnath Mahato a, b, *, Asit Kumar Kar a
a
b

Department of Applied Physics, Indian Institute of Technology (Indian School of Mines) Dhanbad, 826004 Jharkhand, India
Saha Institute of Nuclear Physics (Surface Physics and Material Science Division), 1/AF Bidhannagar, Kolkata 700064, India

a r t i c l e i n f o

a b s t r a c t

Article history:
Received 2 December 2016
Received in revised form
7 April 2017
Accepted 9 April 2017
Available online 15 April 2017

Cadmium selenide (CdSe) thin films have been deposited on indium tin oxide coated glass substrate by
simple electrodeposition method. X-ray Diffraction (XRD) studies identify that the as-deposited CdSe

films are highly oriented to [002] direction and they belong to nanocrystalline hexagonal phase. The
films are changed to polycrystalline structure after annealing in air for temperatures up to 450  C and
begin to degrade afterwards with the occurrence of oxidation and porosity. CdSe completely ceases to
exist at higher annealing temperatures. CdSe films exhibit a maximum absorbance in the violet to bluegreen region of an optical spectrum. The absorbance increases while the band gap decreases with
increasing annealing temperature. Surface morphology also shows that the increase of the annealing
temperature caused the grain growth. In addition, a number of distinct crystals is formed on top of the
film surface. Electrical characteristics show that the films are photosensitive with a maximum sensitivity
at 350  C.
© 2017 The Authors. Publishing services by Elsevier B.V. on behalf of Vietnam National University, Hanoi.
This is an open access article under the CC BY license ( />
Keywords:
CdSe
Thin film
Electrodeposition
XRD
Photosensitivity

1. Introduction
Semiconductors are very important and interesting because of
their technological applications in optoelectronics and microelectronic devices like photodiodes [1], sensors [2], light emitting diodes [3], solar cells [4], photoelectrochemical cells [5], photovoltaic
cells [6] and photodetectors for optical communications etc. Among
them, Cadmium Selenide (CdSe) is a IIeVI group compound semiconducting material of the periodic table. This compound is a
highly photosensitive material in the visible region due to their
suitable band gap (1.74 eV).
Different processes such as chemical vapour deposition [7],
physical vapour deposition [8], thermal evaporation technique [9],
spray-pyrolysis [10], chemical bath deposition [11], dip coating [12]
and electrodeposition [13] have been used for depositing cadmium
selenide thin films. However, the electrodeposition process is one
of the simplest and low-cost techniques because it is easy to

manage and it requires very simple arrangement. Deposition rate is
easily controlled by changing deposition potential, concentration

and pH value of the electrolyte. Many groups are working on cadmium selenide using the process of electrodeposition [5,7,14e16].
The optoelectronic, microelectronic and other applications of
cadmium selenide thin films depend on their structural and electronic properties affecting device performance. These properties
are strongly influenced by the deposition parameters such as
deposition time, deposition potential, concentration of electrolytic
solution, pH of the electrolyte and thermal annealing. Thermal
treatment is one of the important factors to enhance the efficiency
and stability of photosensitive devices. Thus, studies of the effect of
annealing on structural, optical and electrical properties of thin
films are very important in understanding and enhancing device
sensitivity [17e19].
The aim of this present work is to prepare cadmium selenide
thin films by a simple electrodeposition process on indium tin
oxide (ITO) coated glass substrates and to study the effect of
annealing temperature (Ta) on films' photosensitivity. The effect of
annealing on crystallinity, morphology and optical absorbance of
the films are also presented and discussed.

* Corresponding author. Department of Applied Physics, Indian Institute of
Technology (Indian School of Mines) Dhanbad, 826004 Jharkhand, India.
E-mail address: (S. Mahato).
Peer review under responsibility of Vietnam National University, Hanoi.
/>2468-2179/© 2017 The Authors. Publishing services by Elsevier B.V. on behalf of Vietnam National University, Hanoi. This is an open access article under the CC BY license
( />

166

S. Mahato, A.K. Kar / Journal of Science: Advanced Materials and Devices 2 (2017) 165e171

2. Experimental

3.5 mW/cm2) tungsten bulb controlled by a dc power supply and it
was placed 20 cm away from the sample during experiment.

2.1. Film deposition
Cadmium selenide thin films have been deposited on indium tin
oxide coated glass substrates by using a simple two-electrode
electrodeposition process at room temperature (28  C). Sputter
coated ITO/glass was procured from Macwin India, Delhi. The
substrate, having sheet resistance 10 U/sq, was used as a working
electrode or cathode, and a flat graphite rod was used as an anode.
The size of both the electrodes submersed in electrolyte was about
1 Â 1 cm2 and hence the area of deposition was about 1 cm2. The
electrodes were separated by a distance of about 1 cm. Substrates
were cleaned in acetone within an ultrasonic bath for 15 min and
then cleaned in running distilled water for 5 min and, finally, they
were dried in air for 15 min before deposition. For electrodeposition
of the films, cadmium chloride (CdCl2) and selenous acid (H2SeO3)
were used as the sources of cadmium and selenium, respectively in
the electrolyte; the molar concentrations of cadmium chloride and
selenous acid were 0.08 M and 0.005 M, respectively. The electrolyte was continuously stirred for 15 min in a beaker by using a
Teflon coated magnetic paddle attached to a stirrer, in order to
perfectly dissolve the ingredients in distilled water. All the chemicals were procured from Sigma Aldrich and had 99.99% purity. The
total volume of the prepared electrolyte was 100 ml pH. The value
of the electrolyte was kept at 1.9 by using HNO3 solution. The
deposition was conducted for 15 min with a fixed deposition potential of 1.80 V for all the films. After deposition, the thin film
coated substrates were taken out from the electrolyte, then rinsed

in distilled water and dried in air. The as-deposited films were
annealed at 250, 350, 450, 550 and 650  C in the air for one hour in
a muffle furnace with a ramp up rate of 2  C/min followed by
normal cooling to room temperature.
2.2. Reaction mechanism
The reaction mechanism of CdSe thin film is discussed as follows. The deposition process is based on the slow release of Cd2ỵ
ions and Se2 ions in the solution ion-by-ion basis and settling on
the ITO coated glass substrates. The deposition takes place when
the ionic product of Cd2ỵ and Se2À is greater than the solubility
product. Cadmium selenide is deposited according to the following
over-all net reaction [20].

H2 SeO3 ỵ Cd2ỵ ỵ 6e ỵ 4Hỵ #CdSe ỵ 3H2 O
The rate of the formation of CdSe is determined by the bath
parameters such as pH, concentration and temperature of the
electrolyte [21].

3. Results and discussion
3.1. Crystallinity
Cadmium selenide thin film grown on ITO coated glass substrate
is found to be polycrystalline with hexagonal (wurtzite) crystal
structure. Fig. 1(a) shows the XRD pattern of as-deposited or
unannealed CdSe thin film. The peak at 25.99 corresponds to the
plane (002) which is much stronger than other peaks. The intense
peak at (002) suggests a dominant orientation of nanocrystalline
phase of CdSe thin film within an otherwise amorphous or nearly
amorphous matrix. The small hump in the background is due partly
to the amorphous nature of ITO coated glass substrate and also may
be due to some amorphous phase presented in the CdSe thin film
itself [22]. Fig. 1(b)e(f) shows the XRD patterns of annealed films.

Annealing at 250  C [Fig. 1(b)] makes the film more oriented towards (002) plane. The polycrystalline hexagonal CdSe phase is
found after annealing at 350  C [Fig. 1(c)]. Intensity of the most
intense peak is continuously found to decrease with the increase of
annealing temperature. It signifies a gradual change of a highly
oriented nanocrystalline phase to a polycrystalline phase. Further
heat treatment from 450  C to 650  C shows that the CdSe phase
gradually changes to CdO phase [Fig. 1(d)e(f)]. At the annealing
temperature 550  C and above, CdSe completely disappears. All the
XRD patterns from Figs. (d)e(f) show the characteristic diffraction
peaks of (111) and (200) planes of polycrystalline hexagonal CdO
phase. Other peaks (211) at 21.88 , (222) at 30.91, (400) at 35.68
and (622) at 61.18 correspond to ITO. This suggests that the after
annealing of CdSe thin films in air at a higher temperature
[Ta ! 450  C], reaction occurs and chemically a new phase formation takes place; the polycrystalline phase of CdO gradually prevails
over the polycrystalline phase of CdSe with increase in temperature. XRD plots from (a) to (f) also exhibit gradual reduction in
overall peak intensity and hence a rise in background intensity.
They also demonstrate the appearance of more ITO peaks with
enhanced intensity at higher annealing temperature. These facts
might be related to the gradual loss of CdSe and later CdO [Figs. (e)
and (f)] from the surface of the thin films due to sublimation during
annealing and the possibility of diffusion into the substrate may be
ruled out.
Average crystallite size of CdSe films is found to vary from
16.8 nm to 21.9 nm. This was calculated from Scherrer's formula
using full width at half maximum (FWHM) b of the peaks of XRD
profiles [23e25].

D¼
2.3. Film properties
X-ray diffraction (XRD) patterns were recorded using XRD

(BRUKER D8 FOCUS) system with the Cu Ka radiation (l ¼ 1.5406 Å).
qe2q scan was taken for the range of 10 e80 with a speed of 0.20 /
s and with a step size of 0.030 . Optical absorption spectra were
obtained for the region 300 nme900 nm using UVeviseNIR
spectrophotometer. The microstructure and composition of the
CdSe thin films were studied using a scanning electron microscope
(FESEM, Model: JEOL JSM-5800 Scanning Microscope) and energy
dispersive analysis of X-ray (EDAX) module attached with the same
SEM system respectively. The electrical resistivity of the samples
was measured by the two-point probe technique. Currentevoltage
measurements in dark and illumination were accomplished using a
Keithley 2400 source metre. The light source was a 100 W (intensity

Kl
bhkl cos q

(1)

where D ¼ crystallite size, K ¼ shape factor (0.9), and
l ¼ wavelength of Cu Ka radiation.
The microstrain (ε) values have been calculated by using the
following formula:

ε¼

bhkl

(2)

4 tan q

Assuming that, the particle size and strain are independent of
each other, equations (1) and (2) may be combined to the following
form:

bhkl cos q ẳ

Kl
ỵ 4 sin q
D

(3)


S. Mahato, A.K. Kar / Journal of Science: Advanced Materials and Devices 2 (2017) 165e171

167

Fig. 1. XRD patterns of CdSe/ITO thin films at different annealing temperatures: (a) As-deposited, (b) 250  C, (c) 350  C, (d) 450  C, (e) 550  C, and (f) 650  C.

This is known as WilliamsoneHall formula [26]. The graph was
plotted between bhkl cos q versus 4 sin q as shown in Fig. 2. From
the linear fit to the data, the crystallite size was estimated from the
intercept along ordinate, and strain (ε) was found from the slope of
the fit. From WilliamsoneHall (WeH) method the average crystallite size is determined to be 31.5 nm for CdSe thin film annealed
at 450  C.
The dislocation density d has been calculated by using the formula for the highly intense X-ray diffraction peaks.

d¼

15ε
:
aD

(4)

All the calculated values are shown in Table 1. As expected,

increase in annealing temperature leads to increase in crystallite
size, and decrease in strain and dislocation density of the films.
3.2. UVeviseNIR spectroscopy
Fig. 3 shows the variations of optical absorbance and transmittance (inset) with wavelength of the as-deposited and annealed
CdSe thin films. Absorption spectra is strong around the violet to
visible region. Afterwards, it continuously decreases with increase
in wavelength and becomes almost constant at near infrared (NIR)
region for the as-deposited film. For the annealed films, however,
the decrease in absorbance shows a sharp fall at around 700 nm
and then it gradually saturates in the NIR region. The absorbance


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S. Mahato, A.K. Kar / Journal of Science: Advanced Materials and Devices 2 (2017) 165e171

Fig. 2. WeH plot for a film annealed at 450  C.

increases and the broad peak shifts from violet to blue-green region
with increasing annealing temperature. It may be due to increased
crystallite size in the thin films. The colour of the film is found to
change from red-orange to dark black after annealing. The values of

the band gap of the films have been determined from transmission
spectra by using the following relation applicable to near edge
optical absorption of semiconductors:



a¼


Ãn
K Â
hn À Eg
hn

(5)

where a is absorption co-efficient, hn is the photon energy, K is a
constant, Eg is the band gap and n is a constant which equals to ½
for allowed direct band-gap semiconductor in the present case
[27,28]. The band gap energy of CdSe/ITO thin film has been
determined by Tauc plot based on the above formula as shown in
Fig. 4. The optical band gaps are found to be 2.13 eV, 1.95 eV, 1.91 eV
and 1.88 eV for thin films of as-deposited and annealed at 250, 350
and 450  C temperature respectively. The band gap of as-deposited
or unannealed film is higher compared to the annealed CdSe thin
films because the deposition at room temperature gives rise to
films with smaller crystallite size. So the energy band gap of CdSe
thin films tend to decrease as the annealing temperature is
increased due to increased crystallite size of the films.
The value of the extinction coefficient (k) is calculated from the

following relation [29]:

k¼

Fig. 3. UVeviseNIR absorbance and transmittance (inset) spectra of CdSe/ITO thin
films annealed at different temperatures.

al

(6)

4p

The graphical representation of the variation of extinction coefficient with wavelength is shown in Fig. 5. The graph shows that
even for the photons having energy above band gap, the absorption
coefficient is not constant and strongly depends on wavelength. For
photons which have energy very close to that of the band gap, the
absorption is relatively low since only the electrons at the valence

Fig. 4. Tauc plots for as-deposited and annealed CdSe/ITO thin films.

band edge can interact with the photon to cause absorption. As the
photon energy increases, not just the electrons already having
energy close to that of the band gap can interact with the photons, a
larger number of other electrons below band edge can also interact
with the photons resulting in absorption. Thus extinction coefficient has high values near the absorption edge and it has very small
values at higher wavelengths.
3.3. Surface morphology
The surface morphology of as-deposited film and annealed films
has been studied using FESEM as shown in Fig. 6(a)e(f). Surface

Table 1
Structural parameters for as-deposited and annealed CdSe thin films calculated from their corresponding XRD profiles.
Ta ( C)

Crystallite size (nm)

Lattice parameters (Å)
a

c

Unannealed
250
350
450

16.8
18.1
18.2
31.5a

4.24
4.24
4.24
4.24

6.93
6.93
6.93

6.93

a

Calculated from WeH plot.

Strain (ε)

Dislocation density d (Â1017/m2)

0.526
0.492
0.485
0.413a

11.09
9.62
9.43
6.68


S. Mahato, A.K. Kar / Journal of Science: Advanced Materials and Devices 2 (2017) 165e171

Fig. 5. Dispersion curves of extinction coefficient (k) for as-deposited and annealed
CdSe/ITO thin films.

topography of as-deposited film is shown in Fig. 6(a). From the
topograph, it is observed that the as-deposited films are continuous
with homogeneous distribution of densely packed blister-like
particles of nonuniform size varying from several tens of nanometre to about 250 nm. Fig. 6(b) shows a cross-sectional tilted view

of the film annealed at 250  C; spherical nanosized grains of
globule-like structure are observed with several 100 nm in size and
the grains are closely packed with each other to form a crystalline
matrix. A wide view of the corresponding area has been presented
in Fig. 6(e), which covers parts of both cross-sectional and surface
features. It appears that after annealing, the particulate features

169

were more uniform in size, reducing the range of variation
observed in as-deposited films. At the annealing temperature
350  C [Fig. 6(c)], it is found that the films become rougher with the
development of some pebble-like crystalline surface features of
size varying from about 50 nm to 300 nm. Apparently the blisterlike features in figure (a) have played the role of growth centres
and crystalline features are developed through the process of surface and volume diffusion with increase in temperature. The SEM
micrographs of the film annealed at 450  C are shown in Figs. 6(d)
and (f) where the latter represents a wide area view. A drastic
change in crystalline structural features is observed for 100  C increase in annealing temperature with respect to Fig. 6(c). Excellent
single crystalline structures of width as big as 1.5 mm with various
polygon like [30] facets are noticed to evolve on the film surface but
with very less in number compared to the film annealed at 350  C.
Some pores are also found to develop on the surface of the film of
irregular shape appearing like crystalline voids. Other than the
crystals on the surface and the pores, the surface of the film appears
to be smooth with clear demarcation of crystalline grains i.e. grain
boundaries. Grain size varies from about 100 nm to 500 nm. Top
surfaces of the embedded crystalline grains are found to form a nice
mosaic pattern.
Due to annealing, a number of smaller grains or crystals diffuse
and coalesce together to effectively form larger crystalline grains

with clear crystallographic faces. Above mentioned results
demonstrate that the process of annealing induces two parallel
grain growth processes e one within the volume of the thin film
matrix e a primary growth process, and the other over the thin film
surface e a secondary growth process. Crystalline nature of CdSe
thin films is also indicated by XRD measurement.
Thickness of the films was found to be about 6 mm by crosssectional imaging in SEM. Energy dispersive analysis of X-rays
(EDAX) confirms the presence of both Cd and Se in the films. It also
reveals that the thin films annealed at different temperatures are
nonstoichiometric in nature.

Fig. 6. Scanning electron micrographs of CdSe thin films: (a) As-deposited, (b) annealed at 250  C (a tilted cross-sectional view), (c) annealed at 350  C, and (d) annealed at 450  C,
all shown at the same scale for better comparison [5mm  5 mm]; (e) a tilted cross-sectional wide view of (b) [40mm  40 mm] and (f) a large area view of (d) [15mm  15 mm].


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S. Mahato, A.K. Kar / Journal of Science: Advanced Materials and Devices 2 (2017) 165e171

Fig. 7. (a) Currentevoltage characteristics of CdSe thin film annealed at 350  C under dark and illumination conditions; Inset: Schematic diagram of IeV measurement set-up; (b)
Variation of photosensitivity of CdSe thin films with annealing temperature.

area, low cost, and good quality CdSe thin films for photodiode and
photovoltaic applications.

3.4. Electrical property
The electrical resistivity of CdSe/ITO thin film has been
measured by using dc two probe methods. It is determined by
loading a direct current I and measuring a voltage drop V between
two probes which are placed at a distance (s) of 1 mm, using the

following equation [31,32]:

r ¼ 2ps

V
I

(7)

At room temperature the specific conductance was found to be
of the order of 10À4 (UÀ1 cmÀ1).
For photoconductivity measurement of CdSe thin films, area of
the film exposed to light was 1 Â 1 cm2. The dark and illumination
IeV characteristics of CdSe thin films were recorded as shown in
Fig. 7(a) as an example. All the films under dark conditions showed
good rectifying nature. They also responded to illumination giving
rise to photocurrent with again rectifying nature or asymmetric
semiconducting nature. The characteristic curves demonstrated
that the photo response was sensitive to annealing temperature.
The photosensitivity S of the films was calculated using the
following formula:

4. Conclusion
The CdSe thin films have been successfully deposited by a
simple two electrode electrodeposition method on ITO coated glass
substrates. The process of annealing in air has been found to change
the crystallinity of films from highly oriented nanocrystalline
(hexagonal wurtzite) structure to polycrystalline form. With
annealing globular nanocrystalline grains become bigger and a
number of distinct micro-crystals are developed on top of the film

surface; the crystals grow to a maximum in size at 450  C having
clear crystallographic faces on their surface. For annealing temperatures higher than 450  C, CdSe is chemically degraded and is
converted to CdO. The CdSe films exhibit strong absorbance in the
violet to blue-green region. With increase in the annealing temperature, the band gap decreases from 2.13 eV to 1.88 eV for the asdeposited and 450  C films. The CdSe films are photosensitive; the
sensitivity increases with annealing temperature up to 350  C and
then decreases.
Acknowledgements

slight À sdark
s¼
sdark

(8)

where sphoto is the photoconductivity and sdark is the dark conductivity [9]. The as-deposited CdSe thin films show weak photoconductivity and its sensitivity is less (S ~ 3). Annealing at 250  C
reveals increased photoconductivity and its sensitivity increases to
~12. The photoconductivity is found to dramatically improve
(S ~ 64) at 350  C annealing temperature. So it is observed that the
photosensitivity is increased with the increase of annealing temperature as shown in Fig. 7(b). The reason is associated with the
increased absorbance of the incident light in visible region with
increase in annealing temperature. Enhancement in the photoconductivity is due to the generation of more electron-hole pairs
excited by the incident light. Annealing at 450  C leads the
photoconductivity to fall to zero because of the phase change and
accompanying degradation of CdSe thin film. At this temperature,
microstructural defects like pores and formation of secondary
phase like CdO impair and saturate the conduction of charge carriers even after their enhanced generation due to higher absorbance. The result may be beneficial to the development of large

Authors are grateful to Dr. B. Pandey, Dr. N. Das, Dr. D. Roy and
Mr. A. Jana of the Department of Applied Physics, IIT (ISM) Dhanbad, for their assistance in optical and electrical measurements.
References

[1] S. Dayal, N. Kopidakis, D.C. Olson, D.S. Ginley, G. Rumbles, Photovoltaic devices
with a low band gap polymer and CdSe nanostructures exceeding 3% efficiency, Nano Lett. 10 (2010) 239e242.
[2] G. Zou, H. Ju, Electrogenerated chemiluminescence from a CdSe nanocrystal
film and its sensing application in aqueous solution, Anal. Chem. 76 (2004)
6871e6876.
[3] S. Bera, S.B. Singh, S.K. Ray, Green route synthesis of high quality CdSe
quantum dots for applications in light emitting devices, J. Solid State Chem.
189 (2012) 75e79.
[4] S.K. Saha, A. Guchhait, A.J. Pal, Organic/inorganic hybrid pn-junction between
copper phthalocyanine and CdSe quantum dot layers as solar cells, J. Appl.
Phys. 112 (2012) 044e507.
[5] S.K. Shinde, G.S. Ghodake, D.P. Dubal, G.M. Lohar, D.S. Lee, V.J. Fulari, Structural, optical, and photo-electrochemical properties of marygold-like
CdSe0.6Te0.4 synthesized by electrochemical route, Ceram. Int. 40 (2014)
11519e11524.
[6] P.A. Chatea, P.P. Hankareb, D.J. Sathec, Characterization of cadmium selenide
films for photovoltaic applications, J. Alloys Compd. 505 (2010) 140e143.


S. Mahato, A.K. Kar / Journal of Science: Advanced Materials and Devices 2 (2017) 165e171
[7] L.K. Teh, V. Furin, A. Martucci, M. Guglielmi, C.C. Wong, F. Romanato, Electrodeposition of CdSe on nanopatterned pillar arrays for photonic and
photovoltaic applications, Thin Solid Films 515 (2007) 5787e5791.
[8] Y.G. Gudage, R. Sharma, Growth kinetics and photoelectrochemical (PEC)
performance of cadmium selenide thin films: pH and substrate effect, Curr.
Appl. Phys. 10 (2010) 1062e1070.
[9] A. Purohit, S. Chander, S.P. Nehra, C. Lal, M.S. Dhaka, Effect of thickness on
structural, optical, electrical and morphological properties of nanocrystalline
CdSe thin films for optoelectronic applications, Opt. Mater. 47 (2015)
345e353.
[10] A.A. Yadav, M.A. Barote, E.U. Masumdar, Studies on cadmium selenide (CdSe)
thin films deposited by spray pyrolysis, Mater. Chem. Phys. 121 (2010) 53e57.

[11] S. Devadason, M.R. Muhamad, Structural and optical properties of vapour
deposited multi-layer CdSe thin films, Phys. B 393 (2007) 125e132.
[12] P.P. Hankare, P.A. Chate, D.J. Sathe, M.R. Asabe, B.V. Jadha, Photoelectrochemical studies of CdSe thin films deposited by dip method, J. Alloys
Compd. 474 (2009) 347e350.
[13] S. Mahato, N. Shakti, A.K. Kar, Annealing temperature dependent structural
and optical properties of electrodeposited CdSe thin films, Mater. Sci. Semicond. Process. 39 (2015) 742e747.
[14] Z. Gao, W. Jin, Y. Li, Q. Song, Y. Wang, K. Zhang, S. Wang, L. Dai, Flexible solar
cells based on CdSe nanobelt/graphene Schottky junctions, J. Mater. Chem. C
(2015).
[15] S.K. Shinde, D.P. Dubal, G.S. Ghodake, D.S. Lee, G.M. Lohar, M.C. Rath,
V.J. Fulari, Baking impact of Fe composition on CdSe films for solar cell
application, Mater. Lett. 132 (2014) 243e246.
[16] R. Henriquez, A. Badan, P. Grez, E. Munoz, J. Vera, E.A. Dalchiele, R.E. Marotti,
H. Gomeza, Electrodeposition of nanocrystalline CdSe thin films from
dimethyl sulfoxide solution: nucleation and growth mechanism, structural
and optical studies, Electrochim. Acta 56 (2011) 4895e4901.
[17] X. Wang, W. Tian, M. Liao, Y. Bando, D. Golberg, Recent advances in solutionprocessed inorganic nanofilm photodetectors, Chem. Soc. Rev. 43 (2014)
1400e1422.
[18] S.N. Sarangi, S.N. Sahu, CdSe nanocrystalline thin films: composition, structure
and optical properties, Phys. E 23 (2004) 159e167.
[19] S. Chaure, N.B. Chaure, R.K. Pandey, Self-assembled nanocrystalline CdSe thin
films, Phys. E 28 (2005) 439e446.
[20] S. Mahato, A.K. Kar, Structural, optical and electrical properties of electrodeposited cadmium selenide thin films for applications in photodetector and
photoelectrochemical cell, J. Electroanal. Chem. 742 (2015) 23e29.

171

[21] S.M. Pawar, A.V. Moholkar, K.Y. Rajpure, C.H. Bhosale, Electrosynthesis and
characterization of CdSe thin films: optimization of preparative parameters by
photoelectrochemical technique, J. Phys. Chem. Solids 67 (2006) 2386e2391.

[22] R.B. Kale, C.D. Lokhande, Band gap shift, structural characterization and phase
transformation of CdSe thin films from nanocrystalline cubic to nanorod
hexagonal on air annealing, Semicond. Sci. Technol. 20 (2005) 1e9.
[23] S.B. Jambure, C.D. Lokhande, Photoelectrochemical solar cells with chemically
grown CdO rice grains on flexible stainless steel substrates, Mater. Lett. 106
(2013) 133e136.
[24] U. Cevik, E. Bacaksiz, N. Damla, A. Çelik, Effective atomic numbers and electron
densities for CdSe and CdTe semiconductors, Radiat. Meas. 43 (2008)
1437e1442.
[25] C.H. Han, S.D. Han, J. Gwak, S.P. Khatkar, Synthesis of indium tin oxide (ITO)
and fluorine-doped tin oxide (FTO) nano-powder by solegel combustion
hybrid method, Mater. Lett. 61 (2007) 1701e1703.
[26] A.K. Zak, W.H.A. Majid, M.E. Abrishami, R. Yousefi, X-ray analysis of ZnO
nanoparticles by WilliamsoneHall and sizeestrain plot methods, Solid State
Sci. 13 (2011) 251e256.
[27] S.K. Shinde, D.P. Dubal, G.S. Ghodake, V.J. Fulari, Morphological modulation of
Mn:CdSe thin film and its enhanced electrochemical properties, J. Electroanal.
Chem. 727 (2014) 179e183.
[28] S. Mahato, Nanda Shakti, A.K. Kar, Annealing temperature dependent structural and optical properties of electrodeposited CdSe thin films, Mater. Sci.
Semicond. Process. 39 (2015) 742e747.
[29] T.S. Shyju, S. Anandhi, R. Indirajith, R. Gopalakrishnan, Solvothermal synthesis,
deposition and characterization of cadmium selenide (CdSe) thin films by
thermal evaporation technique, J. Cryst. Growth 337 (2011) 38e45.
[30] T.S. Shyju, S. Anandhi, R. Indirajith, R. Gopalakrishnan, Effects of annealing on
cadmium selenide nanocrystalline thin films prepared by chemical bath
deposition, J. Alloys Compd. 506 (2010) 892e897.
[31] S. Erat, H. Metina, M. Ar, Influence of the annealing in nitrogen atmosphere on
the XRD, EDX, SEM and electrical properties of chemical bath deposited CdSe
thin films, Mater. Chem. Phys. 111 (2008) 114e120.
[32] S. Gardelis, P. Manousiadis, A.G. Nassiopoulou, Lateral electrical transport,

optical properties and photocurrent measurements in two-dimensional arrays of silicon nanocrystals embedded in SiO2, Nanoscale Res. Lett. 6 (2011)
227.