1.1 INTRODUCTION
II-VI chalcogenides and oxides are
wide direct bandgap semiconductors with interesting application properties,
with zinc sulphide (ZnS) and zinc oxide (ZnO) being two examples [1]. These
solid solutions for chemicals have the potential to lead to new applications as
well as novel integrations. In ZnS, there are two periods of polymorphism. The
hexagonal wurtzite phase is one, and the cubic sphalerite phase is another
[2-4]. Because of the large differences in size and electronegativity between O
and S (rS/rO = 1.3), [5], it is expected that substituting "O" with
"S" in ZnS will impact the material's electrical and optical
properties. [6]. Bandgap engineering may also be achievable because ZnS and ZnO
have different bandgaps at 300 K [7].
Many optoelectronic devices use
Zn-based materials, including ZnO, ZnS, and Zinc Oxysulphide [8]. Because of
their compositional and crystal structural tunability, Zn (O, S) thin films
[9-11] have recently gained popularity as buffer layers in solar cells, in
addition to being employed as phosphor host materials and photocatalysts [12].
Upon varying their composition, the bandgap [13], the offset of the conduction
band, and the conductivity can be carefully tuned. Furthermore, Zn (O, S) is a
wide bandgap, non-toxic, earth-abundant semiconductor material. As a result, it
is one of the most promising alternatives for CdS in the buffer layer of
chalcopyrite-based thin-film solar cells [7, 14].
Chemical bath deposition and atomic
layer deposition are two efficient pre-processing techniques [15, 16]. Another
desirable deposition process is sputtering [17], which has been extensively
utilized in the manufacturing of other cell layers. Sputtering of an undoped
ZnO layer (i-ZnO) onto the surface of the CdS is necessary for the fabrication
of chalcopyrite cells and modules [18]. This eliminates the requirement for a
separate buffer layer by allowing the sputtered zinc oxide layer as a modification
of the original zinc oxide layer (ZnO) [19]. ZnO and ZnS targets were
co-sputtered to create the Zinc Oxysulphide using the spray method which is
considered one of the most important techniques to prepare thin films [20-23].
Chemical solution (chemical
composition, concentration), the distance between the substrate and atomizer
interaction during film deposition, spray temperatures, substrate homogeneity,
annealing conditions, and spray rates are some of the major factors influencing
the properties of the spray-deposited film [24]. Spraying is an effective
approach for the growth of thin film, multilayer film, thick film, and porous
film on a low-cost substrate [25].
The spray technique has different
advantages including no need for a high-quality substrate and vacuum, the thin
film can be easily doped in the desired proportion, the film’s thickness can be
easily controlled, it is operable at different ranges of moderate temperatures,
no restriction of substrate materials and its dimensions, it is a reliable,
reproducible, and a simple growth method [26, 27].
Several oxides, such as ZnO [28],
CdO [29], TiO2[30], SnO2[31], and NiO [32] have been deposited using the spray
method. This method includes spraying a water/alcohol solution of metal salts
over a heated substrate and then allowing it to break down into an oxide
coating. The breakdown reaction produces oxide, which is thermodynamically
possible and leaves no residue on other reactants. The temperature of the
substrate has a significant impact on the shape of the film. The shape of the
film can be changed from fractured to porous by increasing the temperature [33].
Other critical variables that
determine the characteristics and structure are the types and concentrations of
precursor and additive components [34]. Because of its low crystallinity and
the presence of organic residues, the unannealed spray-deposited layer exhibits
high resistivity, low roughness, and less transparency [35-37]. The properties
of the unannealed film can be enhanced due to thermal annealing, plasma
treatment, and laser treatment [38]. Thermal annealing is one of the easiest
and most successful methods for treating spray-deposited films. The effect of
annealing temperature on the structural, optical, morphological, and thickness
of the Zn (O, S) has been reported by different groups in the literature
[39-41].
Thermal annealing temperatures,
time, and gaseous conditions all affect films and structural flaws in
materials. Dislocations and other structural defects in the material,
adsorption, or breakdown are kept on the surface during the thermal annealing
process; as a result, the structure and stoichiometric ratio of the material is
altered [42]. Common flaws in deposited ZnO films comprise oxygen
interstitials, zinc interstitials, oxygen vacancies, zinc vacancies, and excess
oxygen. The most frequent flaws are zinc interstitial and oxygen vacancies [43,
44].
In this study, the effect of
annealing on zinc oxidized thin film prepared by spray method, and the
stoichiometry of the sprayed material was investigated. The optical properties
were examined to calculate the energy band gap of the zinc oxysulfide thin films.
Furthermore, the field emission microscope was applied to analyse the films'
morphology and (EDX) analysis to confirm the stoichiometry and applicability of
the film for future application.
The maximum paper length is restricted to 12
pages. The manuscript should have the following structure:
1.2
Methodology and
Characterization
Zinc Oxysulphide thin film
nanoparticles were used to prepare thin films at 35˚C which were prepared
using chemical bath deposition from zinc acetate and thiourea precursor. It was
dried using an oven under 50˚C for one hour without a vacuum, then it was
ground to prepare them for deposition. Microscope glass substrates having
dimensions of (1×25 ×75 mm3) were coated with thin Zinc Oxysulphide.
The substrates were cleaned with
distilled water, acetone, and chromic acid immersion for 24 hours. Before
deposition, the substrate was ultrasonically cleaned using ethanol and
distilled before being dried in the desiccator to eliminate the last residue.
In this research, Zinc Oxysulphide thin films were sprayed on the glass
substrate using disposed chemical waste of CBD-ZnS which is the novelty of this
work. The residuals were dried and ground, then examined by EDX to find the
powder composition. The thickness of Zinc Oxysulphide of thin film was measured
by using an optical method.
In the industry, metallic or
ceramic materials are dissolved and then coated to a surface using a thermal
spray technique [45, 46]. During the annealing process, material's physical
and chemical properties are changed and become more suitable for a desired
application [47, 48]. Figure 1 shows the thermal spray system utilized for the
deposition of Zinc Oxysulphide thin films on the glass substrate. In this
study, the solution spray rate was maintained at 3ml/min, and the distance
between the glass substrates and the spray gun atomizer was fixed to 15 cm.
Each thermal spray growth cycle
lasts for three seconds, followed by a ten-second rest period. The waiting
period gives the glass substrate time to reach the necessary temperature for
growth before beginning the subsequent growth thermal spray cycle. The sprayed
film was annealed under different annealing temperatures (150oC, 250oC and
350oC).
1.3
Results And Discussion
The influence of annealing temperatures on
the thickness of Zinc Oxysulphide nanostructured thin film was studied and
shown in Fig. (2).
Figure. 1: Thermal spray deposition system
used for preparing Zinc Oxysulphide thin film.
Figure. 2: Zinc Oxysulphide Growth as a
function of annealing temperature
In this work, before investigating
the influence of annealing temperature on thermally sprayed Zinc Oxysulphide
thin film, the growth temperature and amount of sprayed solution were kept at
T= 35oC, 3ml/min respectively. In the thermal spray growth method, the
substrate temperature performs two primary tasks in addition to providing
mechanical support for the film itself. First, it provides the energy for
chemical reactions and second, it drives the produced particles in the X-Y
plane. As a result, the values of surface roughness and film thickness will
decrease. In addition, it might increase the compactness of the thin film [49].
In this work, the thickness of the
as-deposited Zinc Oxysulphide film was about 190 nm. The increase in the
annealing temperature from 150oC to 350oC resulted in the thickness reduction
due to the re-evaporation of the sprayed solution constituents [28]. XRD
pattern of the as-deposited and annealed (150, 250, and 350˚C) Zn (O, S)
are presented in Fig. 3.
The XRD of the deposited thin films
was carried out using PANanalytical X’Pert Pro X-ray diffractometer with
CuKα radiation of wavelength, λ = 1.5406 Å, at 35kV/40 mA. The
as-deposited and the annealed films are shown to be amorphous [JCPDS (01-079-0205].
There are several studies in the literature reporting the growth of both
crystalline and amorphous Zn (O, S) mainly depending on the growth and
annealing conditions [50-52].
Figure. 3: XRD patterns of Zinc Oxysulphide
as-deposited and annealed at 150, 250, and 350˚C.
Figures 4 and 5 show the EDX
spectrum and FESEM image of the Zn (O, S) obtained from the ground and dried
disposal of CBD-ZnS and then annealed at 50oC for one hour in the furnace. The
EDX spectrum elucidates the presence of elemental oxygen, zinc, and sulphur in
the deposited thin film. The FESEM of the Zn (O, S) powder shows approximately
large spherically-shaped grains with their size between ~ (50-250) nm.
Different research groups have also reported the EDX spectra of Zn (O, S)
deposited using different growth techniques and the EDX results reported in
this work are similar to those reported in the literature [53-55].
Figure. 4: EDX spectrum of as-deposited
zinc oxysulfide thin film.
The effect of annealing temperature
on the morphology of thermally sprayed zinc oxysulfide thin film has been
studied and is shown in Figure 6 (b-d). For the as-deposited Zn (O, S), the
FESEM shows a flower-like morphology with different nanoparticle sizes as shown
in Figure 6a. When the film was annealed for one hour under the temperature of
150˚C, a cone-like and leaf-like morphology with different nanoparticle
sizes and small cracks appeared, as displayed in Fig. 6b. Also, nanoparticles
were non-uniformly distributed on the surface of the substrate having tiny gaps
in between the agglomerated nanoparticles.
Figure 5: The FESEM image of the prepared
Zn (O, S) powder annealed at 50oC for one hour in the furnace.
Figure. 6: Effect of annealing temperatures on spray-deposited Zinc Oxysulphide
thin film a) as-deposited, at b)150°C, c)250°C, and d)350°C.
By increasing the annealing
temperature to 250˚C the cracks in the surface of the nanoparticles
disappeared, the cone-like nanoparticle morphology became more compact and the
gaps in between the agglomerated nanoparticles were reduced as shown in Figure
6c. When the annealing temperature was increased to 350oC, the gaps between the
nanoparticle clusters were increased, the compactness of the film morphology
was reduced and the cracks on the surface of the cone-liked agglomerated
nanoparticle became more visible (see Fig. 6d). From the observation of this
work and comparison of the other works on the Zn (O, S) the annealing
temperature has prominent effect on the morphology, shape and size of the
nanoparticles [56-58].
The optical properties of all the
samples were investigated using UV-Vis spectrophotometer model 6850 Jenway with
a scanning range of (190-1100) nm. The transmittance values of the thermally
sprayed Zn (O, S) thin films were determined and plotted as shown in Fig. 7a.
The transmittance of the as-deposited and annealed Zn (O, S) films was
approximately similar and their transmittance percentages were in the range of
(62 to 65) %. When the annealing temperature increased to 150 and 250oC, the
transmittance percentage was reduced to the range of (45-47) % and (32-35) %,
respectively. To calculate the energy band gap a relationship between
(αhυ)2 and photon energy was plotted, as exhibited in Fig. 7b.
Figure. 7: shows the effect of various
annealing temperatures on the energy bandgap of Zn (O, S) thin film.
For the as-deposited film, the
measured bandgap value was approximately 3.99 eV. When the annealing
temperature was increased to, 150, 250, and 350oC, the bandgap values were
reduced to 3.98, 3.95, and 3.92 eV, respectively [See table 1]. The reduction in
the bandgap can be attributed to the increase in the nanoparticle size with
increasing annealing temperature. The observed high bandgap values of the
as-deposited and annealed Zn (O, S) can be related to the nanoparticle nature
of the deposited and annealed Zn (O, S) films and the quantum confinement
effect[59-62] .It is worth mentioning that the high value of obtained band
energy can also be related to the FESEM graph [see Fig. 6 (a-b)], as it can be
seen that the deposited nanoparticles are non-uniformly distributed on the
glass substrate forming gaps in between grains. These gaps open up the pass for
light to pass through during optical absorption measurement which can result in
higher bandgap value observation and slight measurement error in the bandgap
values should be considered.
Table 1. Variation of energy gaps as a
function of annealing temperatures
|
Annealing Temp. Eg
(±0.02) eV
150
3.98
250
3.95
350
3.92
|
1.5. Conclusion
Zn (O, S) were successfully
prepared from the disposed CBD-ZnS and deposited on the glass substrate using
the thermal spray growth method. The XRD pattern elucidates the amorphous
nature of the deposited and annealed film. The EDX spectrum confirms the presence
of elemental oxygen, zinc, and sulfur in the deposited thin film. The FESEM of
the deposited and annealed Zn (O, S) film shows cone-like flower morphology
with different nanoparticle shapes and sizes. The annealing temperature
prominently affects the particle distribution and compactness of the
nanoparticles. The optical absorption measurement indicated a bandgap reduction
with increasing
Annealing temperature due to
nanoparticle size growth, nature, and quantum confinement effect. Based on the
XRD, EDX, FESEM, and optical properties of the deposited Zn (O, S) using the
thermal spray method in this study, the prepared films can be used for wide
bandgap optoelectronic applications.
Acknowledgements (optional)
Authers would like to thank
University of Duhok College of Science Department of Physics for their support
to this research.
References
Abe, Y., Komatsu, A., Nohira, H., Nakanishi, K., Minemoto, T.,
Ohta, T., & Takakura, H. (2012). Interfacial layer formation at ZnO/CdS
interface. Applied Surface Science, 258(20), 8090-8093.
Algadri, N. A., AL-Diabat, A. M., & Ahmed, N. M. (2023). Zinc
sulfide based thin film photodetector prepared by spray pyrolysis.
Instrumentation Science & Technology, 51(2), 144-161.
Ardekani, S. R., Aghdam, A. S. R., Nazari, M., Bayat, A., Yazdani,
E., & Saievar-Iranizad, E. (2019). A comprehensive review on ultrasonic
spray pyrolysis technique: Mechanism, main parameters and applications in
condensed matter. Journal of Analytical and Applied Pyrolysis, 141, 104631.
Ashour, A., Kaid, M., El-Sayed, N., & Ibrahim, A. (2006).
Physical properties of ZnO thin films deposited by spray pyrolysis technique.
Applied Surface Science, 252(22), 7844-7848.
ávan der Put, P. J. (1996). Morphology control of thin LiCoO 2 films
fabricated using the electrostatic spray deposition (ESD) technique. Journal of
Materials Chemistry, 6(5), 765-771.
Axinte, E. (2011). Glasses as engineering materials: A review.
Materials & Design, 32(4), 1717-1732.
Bakke, J. R., Tanskanen, J. T., Hägglund, C., Pakkanen, T. A., &
Bent, S. F. (2012a). Growth characteristics, material properties, and optical
properties of zinc oxysulfide films deposited by atomic layer deposition.
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films,
30(1), 01A135.
Bakke, J. R., Tanskanen, J. T., Hägglund, C., Pakkanen, T. A., &
Bent, S. F. (2012b). Growth characteristics, material properties, and optical
properties of zinc oxysulfide films deposited by atomic layer deposition.
Journal of Vacuum Science & Technology A, 30(1).
Basnet, P., Samanta, D., & Chatterjee, S. (2021). Chemical
Approach Based ZnS-ZnO Nanocomposite Synthesis and Assessment of their
Structural, Morphological and Photocatalytic Properties.
Belkhalfa, H., Ayed, H., Hafdallah, A., Aida, M., & Ighil, R. T.
(2016). Characterization and studying of ZnO thin films deposited by spray
pyrolysis: effect of annealing temperature. Optik, 127(4), 2336-2340.
Bhateja, A., Varma, A., Kashyap, A., & Singh, B. (2012). Study
the effect on the hardness of three sample grades of tool steel ie EN-31, EN-8,
and D3 after heat treatment processes such as annealing, normalizing, and
hardening & tempering. The International Journal of Engineering And Science
(IJES), 1(2).
Brinzari, V., Korotcenkov, G., & Golovanov, V. (2001). Factors
influencing the gas sensing characteristics of tin dioxide films deposited by
spray pyrolysis: understanding and possibilities of control. Thin solid films,
391(2), 167-175.
Bugot, C., Schneider, N., Jubault, M., Lincot, D., & Donsanti,
F. (2015). Temperature effect on zinc oxysulfide-Zn (O, S) films synthesized by
atomic layer deposition for Cu (In, Ga) Se2 solar cells. Journal of Vacuum
Science & Technology A, 33(1).
Caglar, M., Ilican, S., Caglar, Y., & Yakuphanoglu, F. (2008).
The effects of Al doping on the optical constants of ZnO thin films prepared by
spray pyrolysis method. Journal of Materials Science: Materials in Electronics,
19(8), 704-708.
Chelvanathan, P., Yusoff, Y., Haque, F., Akhtaruzzaman, M., Alam,
M., Alothman, Z., . . . Amin, N. (2015). Growth and characterization of
RF-sputtered ZnS thin film deposited at various substrate temperatures for
photovoltaic application. Applied Surface Science, 334, 138-144.
Dadlani, A. L., Trejo, O., Acharya, S., Torgersen, J., Petousis, I.,
Nordlund, D., . . . Prinz, F. B. (2015). Exploring the local electronic
structure and geometric arrangement of ALD Zn (O, S) buffer layers using X-ray
absorption spectroscopy. Journal of Materials Chemistry C, 3(47), 12192-12198.
Deulkar, S. H., Huang, J.-L., & Neumann-Spallart, M. (2010a).
Zinc oxysulfide thin films grown by pulsed laser deposition. Journal of
electronic materials, 39(5), 589-594.
Deulkar, S. H., Huang, J.-L., & Neumann-Spallart, M. (2010b).
Zinc oxysulfide thin films grown by pulsed laser deposition. Journal of
electronic materials, 39, 589-594.
Du Ahn, B., Oh, S. H., Lee, C. H., Kim, G. H., Kim, H. J., &
Lee, S. Y. (2007). Influence of thermal annealing ambient on Ga-doped ZnO thin
films. Journal of crystal growth, 309(2), 128-133.
Earis, P., Montgomery, H., Weatherby, S., Frame, R., Chen, F.,
Bergius, W., . . . Smekal, T. (2013). www. rsc. org/nanoscale. Nanoscale,
5(1849), 1768-1771.
Echendu, O., Werta, S., Dejene, F., & Craciun, V. (2018).
Electrochemical deposition and characterization of ZnOS thin films for
photovoltaic and photocatalysis applications. Journal of alloys and compounds,
769, 201-209.
Erdoğan, E., & Kiyak Yildirim, A. (2023). Synthesis of
Zn-doped lead sulphide by electrodeposition: potential change on structural,
morphological, and optical properties. Journal of Materials Science: Materials
in Electronics, 34(10), 880.
Galedari, S. A., Mahdavi, A., Azarmi, F., Huang, Y., & McDonald,
A. (2019). A comprehensive review of corrosion resistance of thermally-sprayed
and thermally-diffused protective coatings on steel structures. Journal of
Thermal Spray Technology, 28, 645-677.
Golshahi, S., Rozati, S., Martins, R., & Fortunato, E. (2009).
P-type ZnO thin film deposited by spray pyrolysis technique: The effect of
solution concentration. Thin solid films, 518(4), 1149-1152.
Grimm, A., Kieven, D., Lauermann, I., Lux-Steiner, M. C., Hergert,
F., Schwieger, R., & Klenk, R. (2012). Zn (O, S) layers for chalcoyprite
solar cells sputtered from a single target. EPJ Photovoltaics, 3, 30302.
Heikkinen, I. (2016). Characterization of zinc oxide, sulfide and
oxysulfide thin films grown by spatial atomic layer deposition.
Hsieh, T.-M., Lue, S. J., Ao, J., Sun, Y., Feng, W.-S., & Chang,
L.-B. (2014). Characterizations of chemical bath-deposited zinc oxysulfide
films and the effects of their annealing on copper–indium–gallium–selenide
solar cell efficiency. Journal of Power Sources, 246, 443-448.
Islam, M. M., Ishizuka, S., Yamada, A., Sakurai, K., Niki, S.,
Sakurai, T., & Akimoto, K. (2009). CIGS solar cell with MBE-grown ZnS
buffer layer. Solar energy materials and solar cells, 93(6-7), 970-972.
Jani, M., Raval, D., Pati, R., Mukhopadhyay, I., & Ray, A.
(2017). Structure, optical and electronic properties of solid solution Zn (O,
S) thin films and the effect of annealing. Applied Physics A, 123, 1-8.
Jones, A. C., & Hitchman, M. L. (2009). Overview of chemical
vapour deposition. Chemical Vapour Deposition: Precursors, Processes and
Applications, 1, 1-36.
Jule, L. T. (2017). Theoretical and experimental study of core-shell
structured ZnO/ZnS and growth mechanism of un-doped and doped ZnO
nanomaterials. University of the Free State (Qwaqwa Campus).
Kang, H. S., Kang, J. S., Kim, J. W., & Lee, S. Y. (2004).
Annealing effect on the property of ultraviolet and green emissions of ZnO thin
films. Journal of applied physics, 95(3), 1246-1250.
Karamdel, J., Dee, C., & Majlis, B. Y. (2011). Effects of
annealing conditions on the surface morphology and crystallinity of sputtered
ZnO nano films. Sains Malaysiana, 40(3), 209-213.
Kaur, J., & Pandey, O. (2010). Synthesis and Photo-Catalytic
Studies of ZnS Nanoparticles.
Khalil, M. H., Mohammed, R. Y., & Ibrahem, M. A. (2021). The
influence of CBD parameters on the energy gap of ZnS Narcissus-like
nanostructured thin films. Coatings, 11(9), 1131.
Khalil, M. H., Mohammed, R. Y., & Ibrahem, M. A. (2022).
Influence of post annealing on CBD deposited ZnS thin films. Paper presented at
the AIP Conference Proceedings.
King, M., McClure, W., Andrews, L., & Holomery, M. (1992).
Powder diffraction file alphabetic index, inorganic phases/organic phases.
International Center for Diffraction Data, Newtown Square, Pa, USA.
Korotcenkov, G., Brinzari, V., Schwank, J., & Cerneavschi, A.
(2002). Possibilities of aerosol technology for deposition of SnO2-based films
with improved gas sensing characteristics. Materials Science and Engineering:
C, 19(1-2), 73-77.
Krunks, M., & Mellikov, E. (1995). Zinc oxide thin films by the
spray pyrolysis method. Thin solid films, 270(1-2), 33-36.
Kumar, M. (2019). Effect of substrate temperature on surface
morphology and optical properties of sputter deposited nanocrystalline nickel
oxide films. Materials Research Express, 6(9), 096404.
Lu, H.-Y., Chu, S.-Y., & Tan, S.-S. (2004). The characteristics
of low-temperature-synthesized ZnS and ZnO nanoparticles. Journal of crystal
growth, 269(2-4), 385-391.
Marimuthu, S., Sezer, H. K., & Kamara, A. M. (2019).
Applications of laser cleaning process in high value manufacturing industries
Developments in surface contamination and cleaning: applications of cleaning
techniques (pp. 251-288): Elsevier.
Natarajan, C., Fukunaga, N., & Nogami, G. (1998). Titanium
dioxide thin film deposited by spray pyrolysis of aqueous solution. Thin solid
films, 322(1-2), 6-8.
Okamoto, A., Minemoto, T., & Takakura, H. (2011). Application of
Sputtered ZnO1-xSx Buffer Layers for Cu (In, Ga) Se2 Solar Cells. Japanese
journal of applied physics, 50(4S), 04DP10.
Patil, P., & Kadam, L. (2002). Preparation and characterization
of spray pyrolyzed nickel oxide (NiO) thin films. Applied Surface Science,
199(1-4), 211-221.
Patil, P. S. (1999). Versatility of chemical spray pyrolysis
technique. Materials Chemistry and physics, 59(3), 185-198.
Perednis, D., & Gauckler, L. J. (2005). Thin film deposition
using spray pyrolysis. Journal of electroceramics, 14, 103-111.
Persson, C., Platzer-Björkman, C., Malmström, J., Törndahl, T.,
& Edoff, M. (2006). Strong valence-band offset bowing of ZnO 1− x S x
enhances p-type nitrogen doping of ZnO-like alloys. Physical review letters,
97(14), 146403.
Platzer-Björkman, C., Törndahl, T., Abou-Ras, D., Malmström, J.,
Kessler, J., & Stolt, L. (2006). Zn (O, S) buffer layers by atomic layer
deposition in Cu (In, Ga) Se2 based thin film solar cells: Band alignment and
sulfur gradient. Journal of applied physics, 100(4).
Polat, İ., Aksu, S., Altunbaş, M., & Bacaksız, E.
(2012). The influence of diffusion temperature on the structural, optical, and
magnetic properties of nickel‐doped zinc oxysulfide thin films. physica status solidi (a), 209(1),
160-166.
Riad, A., Mahmoud, S., & Ibrahim, A. (2001). Structural and DC
electrical investigations of ZnO thin films prepared by spray pyrolysis
technique. Physica B: Condensed Matter, 296(4), 319-325.
Sagar, P., Shishodia, P., Mehra, R., Okada, H., Wakahara, A., &
Yoshida, A. (2007). Photoluminescence and absorption in sol–gel-derived ZnO
films. Journal of Luminescence, 126(2), 800-806.
Salam, S., Islam, M., Alam, M., Akram, A., Ikram, M., Mahmood, A., .
. . Mujahid, M. (2011). The effect of processing conditions on the structural
morphology and physical properties of ZnO and CdS thin films produced via
sol–gel synthesis and chemical bath deposition techniques. Advances in Natural
Sciences: Nanoscience and Nanotechnology, 2(4), 045001.
Sanders, B., & Kitai, A. (1992). Zinc oxysulfide thin films
grown by atomic layer deposition. Chemistry of materials, 4(5), 1005-1011.
Vanjari, R., & Singh, K. N. (2015). Utilization of methylarenes
as versatile building blocks in organic synthesis. Chemical Society Reviews,
44(22), 8062-8096.
Vigil, O., Cruz, F., Morales-Acevedo, A., Contreras-Puente, G.,
Vaillant, L., & Santana, G. (2001). Structural and optical properties of
annealed CdO thin films prepared by spray pyrolysis. Materials Chemistry and
physics, 68(1-3), 249-252.
Wahab, R., Ansari, S., Kim, Y.-S., Dhage, M., Seo, H. K., Song, M.,
& Shin, H.-S. (2009). Effect of annealing on the conversion of ZnS to ZnO
nanoparticles synthesized by the sol-gel method using zinc acetate and
thiourea. Metals and Materials International, 15, 453-458.
Wang, L., Pu, Y., Fang, W., Dai, J., Zheng, C., Mo, C., . . . Jiang,
F. (2005). Effect of high-temperature annealing on the structural and optical
properties of ZnO films. Thin solid films, 491(1-2), 323-327.
Zazueta-Raynaud, A., Cordova-Rubio, A., Lopez-Delgado, R.,
Pelayo-Ceja, J. E., Carrillo-Torres, R., Sanchez-Zeferino, R., . . . Ayon, A.
(2019). ZnS and ZnO nanocomposite for near white light tuning applications.
Paper presented at the 2019 Symposium on Design, Test, Integration &
Packaging of MEMS and MOEMS (DTIP).
Zhao, J., Song, P., Feng, L., Wang, X., & Tang, Z. (2023).
Theoretical insights into atomic-electronegativity-regulated ESIPT behavior for
B-bph-fla-OH fluorophore. Journal of Molecular Liquids, 380, 121763.
Zhu, X., Defaÿ, E., Aïd, M., Ren, Y., Zhang, C., Zhu, J., . . .
Xiao, D. (2013). Preferential growth and enhanced dielectric properties of Ba0.
7Sr0. 3TiO3 thin films with preannealed Pt bottom electrode. Journal of Physics
D: Applied Physics, 46(10), 105301.
Zhu, Y., Yamazaki, T., Chen, Z., Hirose, Y., Nakao, S., Harayama,
I., . . . Hasegawa, T. (2020). High‐Mobility and Air‐Stable Amorphous Semiconductor Composed of Earth‐Abundant Elements: Amorphous Zinc Oxysulfide. Advanced Electronic
Materials, 6(1), 1900602.
