Deposition Of Cu Research Articles

Impact of Abandoned Mining Facility Wastes on the Aquatic Ecosystem of the Mogpog River, Marinduque, Philippines.

Background.Mine waste from abandoned mining sites can cause environmental degradation and ecological imbalance to receiving water bodies. Heavy metal pollution affects local communities and may pose health risks to the general public. An abandoned mining facility in Marinduque, Philippines, situated on the of Mogpog River, continuously deposits mine wastes, which may affect the river and the health of local communities.Objectives.The aim of the present study was to examine the presence and extent of heavy metal contamination from mine wastes in the aquatic ecosystem of the Mogpog River by determining the level of heavy metal concentration in the water, sediments and biota.Methods.Four sampling sites were monitored for heavy metals (copper (Cu), arsenic (As), chromium (Cr) and sulfur (S)) pollution. Several analyses were conducted to determine the heavy metals present in the water, sediment and biota. Atomic absorption spectrophotometry was used for the analysis of Cu concentrations in water. X-ray fluorescence was used for the analysis of total heavy metals in the sediments and biota.Results.An inverse relationship with water and sediment from upstream to downstream of the river were observed. This trend shows deposition of Cu in the sediments as factored by pH. Flora gathered from the riverbanks recorded concentrations of Cu in their leaves and fruits.Conclusions.It has been difficult for the Mogpog River to regain water quality after years of mine waste deposition. Acid mine drainage occurred upstream of the river which affects the speciation of heavy metals. The potential risk of heavy metal exposure to local communities was observed due to the communities' river utilization.Participant Consent.ObtainedEthics Approval.The Office of Vice Chancellor for Research and Extension of University of the Philippines Los Baños approved the studyCompeting Interests.The authors declare no competing financial interests.

A Novel Metal Precursor Structure for Electrodepositing Ultrathin CIGSe Thin-Film Solar Cell with High Efficiency.

The two-step process of electrodeposition and selenization is one of the most effective methods for producing CIGSe and CZTSe solar cells at a low cost. However, it is difficult to prepare the ultrathin CIGSe absorber by electrodeposition due to the nonuniform deposition of Cu on the Mo substrate. In this study, Cu was deposited on a Sb film instead of a Mo film, and the 3D growth mode of Cu was changed. Uniform and smooth ultrathin Cu films were fabricated on the Sb film using a pulse frequency over a range from 1000 to 10,000 Hz and a pulse current density ranging from 31.25 to 62.5 mA/cm2. Owing to the improved uniformity of Cu/In/Ga films, the thickness of the CIGSe absorber was reduced from 2 to 0.36 μm with Sb incorporation. In addition, the effects of Sb-doping on the CIGSe absorbers and the device performance were investigated. The crystallinity of the CIGSe films was improved, and the interface recombination of the solar cells was reduced by Sb incorporation. Ultimately, CIGSe thin-film solar cells with efficiencies of 5.25 and 11.27% were obtained with CIGSe absorber thicknesses of 0.36 and 1.2 μm, respectively.

Non-equilibrium growth of metal clusters on a layered material: Cu on MoS2

We use a variety of experimental techniques to characterize Cu clusters on bulk MoS2 formed via physical vapor deposition of Cu in ultrahigh vacuum, at temperatures ranging from 300 K to 900 K. We find that large facetted clusters grow at elevated temperatures, using high Cu exposures. The cluster size distribution is bimodal, and under some conditions, large clusters are surrounded by a denuded zone. We propose that defect-mediated nucleation, and coarsening during deposition, are both operative in this system. At 780 K, a surprising type of facetted cluster emerges, and at 900 K this type predominates: pyramidal clusters with a triangular base, exposing (311) planes as side facets. This is a growth shape, rather than an equilibrium shape.

Comparison between sinusoidal AC coagulation and conventional DC coagulation in removing Cu2+ from printed circuit board wastewater.

A new Electrocoagulation (EC) technique, sinusoidal AC coagulation (SACC), is creatively put forward for Cu2+ removal in the wastewater from the printed circuit board (PCB) production in this paper. The removal efficiency of Cu2+ from PCB wastewater and energy consumption are compared by SACC and conventional direct current coagulation (DCC). The optimal process parameters were established through analysis of response surface methodology (RSM). The coagulations containing Cu2+ was characterized by SEM, EDS, TEM，BET, XRD and FTIR. The nano-ferrum collosol, mainly composed of goethite (α-FeOOH) and magnetite (γ-Fe2O3), absorbs the Cu2+ and coagulates to remove Cu2+. The results show that the removal rates of Cu2+ by SACC and DCC are 99.86％ and 98.21％, respectively, and the energy consumption is 2.76×10-2kWh⋅m-3 for SACC and 4.42×10-2kWh⋅m-3 for DCC under the optimal process conditions of c0 (Cu2+)=41.99mg⋅dm-3, pH=7.14, j=0.293 A⋅m-2, t=16.7min. The pilot tests indicate that the SACC technique is feasible in industrial application. Cu2+ removal were completed through electrodeposition of Cu2+ on iron electrode, the deposition of Cu(OH)2 and the adsorption of Cu2+ by ferrum collosol. The adsorption follows the pseudo-second order kinetics model well. The maximum saturated adsorption capacity (qmax) of Cu2+ on ferrum collosol produced by SACC is larger than that by DCC. The adsorption of Cu2+ on the ferrum collosol prepared by SACC and DCC are in accordance with Langmuir's adsorption isotherms. The novel SACC technique is a promising technique for the highly-efficient treatment of Cu2+ from PCB wastewater.

Growth and aggregation of Cu nanocrystals on ionic liquid surfaces**Project supported by the National Natural Science Foundation of China (Grant No. 11374082).

We report a catalyst-free growth of Cu nanocrystals on ionic liquid surfaces by thermal evaporation method at room temperature. After deposition of Cu on ionic liquid surfaces, ramified Cu aggregates form. It is found that the aggregates are composed of both granules and nanocrystals with triangular or hexagonal appearances. The sizes of the nanocrystals are in the range of tens to hundreds of nanometers and increase with the nominal deposition thickness. The growth mechanism of the Cu aggregates and nanocrystals is presented.

Electrophoretic Deposition of Copper(II)-Chitosan Complexes for Antibacterial Coatings.

Bacterial infection associated with medical implants is a major threat to healthcare. This work reports the fabrication of Copper(II)–Chitosan (Cu(II)–CS) complex coatings deposited by electrophoretic deposition (EPD) as potential antibacterial candidate to combat microorganisms to reduce implant related infections. The successful deposition of Cu(II)–CS complex coatings on stainless steel was confirmed by physicochemical characterizations. Morphological and elemental analyses by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy verified the uniform distribution of copper in the Chitosan (CS) matrix. Moreover, homogeneous coatings without precipitation of metallic copper were confirmed by X-ray diffraction (XRD) spectroscopy and SEM micrographs. Controlled swelling behavior depicted the chelation of copper with polysaccharide chains that is key to the stability of Cu(II)–CS coatings. All investigated systems exhibited stable degradation rate in phosphate buffered saline (PBS)–lysozyme solution within seven days of incubation. The coatings presented higher mechanical properties with the increase in Cu(II) concentration. The crack-free coatings showed mildly hydrophobic behavior. Antibacterial assays were performed using both Gram-positive and Gram-negative bacteria. Outstanding antibacterial properties of the coatings were confirmed. After 24 h of incubation, cell studies of coatings confirms that up to a certain threshold concentration of Cu(II) were not cytotoxic to human osteoblast-like cells. Overall, our results show that uniform and homogeneous Cu(II)–CS coatings with good antibacterial and enhanced mechanical stability could be successfully deposited by EPD. Such antibiotic-free antibacterial coatings are potential candidates for biomedical implants.

Preparation and conductive property of Cu coatings and Cu-graphene composite coatings on ABS substrate

A facile, low-cost and environmentally-friendly technique has been developed to prepare highly conductive copper-graphene nanosheet (Cu-GNS) composite coatings on ABS (Acrylonitrile-Butadiene-Styrene) substrate. The surface activation of ABS substrate was obtained by a chrome-free and palladium-free pretreatment consisting of molecular bonding. Before electroplating Cu, the homogeneous single Ag film on ABS surface was achieved by the electroless spray-plating process. In addition, the deposition of Cu and GNS increased in the coatings along with the current density increasing. Four-point-probe test confirmed that the resistivity of Cu coatings (0.08 mΩ mm) and Cu-GNS composite coatings (0.05 mΩ mm) was in the same order of magnitude as pure copper (0.0175 mΩ mm) at high current density. Meanwhile, comparing with the Cu coatings, the resistivity of Cu-GNS composite coatings was reduced by nearly 40% at the same current density. The conductive property was significantly improved owing to the deposition of GNS. Therefore, this work was expected to expand the method of polymer materials surface metallization.

Enhanced copper–carbon nanotube hybrid conductors with titanium adhesion layer

Cu–carbon nanotube (CNT) hybrids combine the advantages of the high electrical conductivity of Cu with the low temperature coefficient of resistance for CNTs, but require enhanced interfacing to improve the electrical performance when exposed to elevated temperatures. Herein, Ti and Ni were investigated as adhesion metals by thermally evaporating 10 nm layers onto a CNT conductor. SEM analysis shows Ni deposits as discrete nanoscale crystallites which coalesce after annealing to 400 °C in H2/Ar. Ti deposits uniformly along the CNT surface and is stable over such temperatures. A 100 nm deposition of Cu is shown to delaminate from the CNTs after annealing, and the resistance per length (R/L) increases by 40%. The Cu–Ni–CNT exhibits a 125% increase, while the Cu–Ti–CNT achieves a 12% decrease in R/L, for similar annealing conditions. Thus, Ti emerges as an effective adhesion metal, warranting its use in metal–CNT wire technologies for elevated temperature operation.

A New Alternative Electrochemical Process for a Pre-Deposited UPD-Mn Mediated the Growth of Cu(Mn) Film by Controlling the Time during the Cu-SLRR

A layer-by-layer deposition is essential for fabricating the Cu interconnects in a nanoscale-sized microelectronics because the gap-filling capability limits the film deposition step coverage on trenches/vias. Conventional layer-by-layer electrochemical deposition of Cu typically works by using two electrolytes, i.e., a sacrificial Pb electrolyte and a Cu electrolyte. However, the use of a Pb electrolyte is known to cause environmental issues. This study presents an Mn monolayer, which mediated the electrochemical growth of Cu(Mn) film through a sequence of alternating an underpotential deposition (UPD) of Mn, replacing the conventionally used UPD-Pb, with a surface-limited redox replacement (SLRR) of Cu. The use of the sacrificial Mn monolayer uniquely provides redox replacement by Cu2+ owing to the standard reductive potential differences. Repeating the sequence of the UPD-Mn followed by the SLRR-Cu enables Cu(Mn) film growth in an atomic layer growth manner. Further, controlling the time of open circuit potential (OCP) during the Cu-SLRR yields a technique to control the content of the resultant Cu(Mn) film. A longer OCP time caused more replacement of the UPD-Mn by the Cu2+, thus resulting in a Cu(Mn) film with a higher Cu concentration. The proposed layer-by-layer growth method offers a wet, chemistry-based deposition capable of fabricating Cu interconnects without the use of the barrier layer and can be of interest in microelectronics.

Влияние коронного разряда на оптические свойства тонкопленочных структур Cu-As-=SUB=-2-=/SUB=-Se-=SUB=-3-=/SUB=-

Effect of corona discharge on holographic recording of diffraction gratings in Cu-As2Se3 thin film structure was studied. Thin film structures of Cu-As2Se3 were prepared on glass substrates by sequential deposition of Cu and As2Se3 layers using vacuum thermal evaporation technique. Applying of negative corona discharge during recording procedure caused an enhancing both of the holographic sensitivity and diffraction efficiency of the grating. Exposure to actinic light illumination resulted in photodarkening effect in Cu-As2Se3 thin film structure in the spectrum region of strong absorption. At the same time the fotoinduced bleaching of Cu-As2Se3 film structure in the spectrum region of weak absorption was observed. Negative corona discharge applied during the light exposure enhanced the bleaching, while positive corona discharge caused its weakening. The photoinduced diffusion of Cu+ ions into As2Se3 film was considered to explain qualitatively the experimental results.

Growth of Cu(In,Ga)Se2 thin films by a novel single flash thermal evaporation source

A novel route of a single flash thermal evaporation technique has been used for deposition of Cu(In,Ga)Se2. This route allows the deposition of stoichiometric CIGS layers direct from powder elements without selenization or any treatment. Structure, optical properties and surface morphology of the deposited films at various substrate temperatures have been investigated using X-ray diffraction (XRD) analysis, Raman spectroscopy, photospectroscopy, Scanning electron microscopy (SEM) and Atomic force microscopy. The structure and the optical properties of deposited films depend on the substrate temperatures which play crucial rule on the stoichiometry of the film by changing mainly the content of selenium. Increasing the substrate temperature improved the crystallinity of the films and the best stoichiometric film has been found at 220°C, the grain size increased from 146 to 286 Å, Whereas, the band gap reduced to 1.37 eV.

Trace element geochemistry of magnetite and pyrite and sulfur isotope geochemistry of pyrite and barite from the Thanewasna Cu-(Au) deposit, western Bastar Craton, central India: Implication for ore genesis

The Thanewasna copper belt in Bastar Craton of central India is well-known for Cu ± Au mineralization. In this study, we use major and trace element chemistry of magnetite, hematite, and pyrite, as well as the sulfur isotope composition of chalcopyrite, pyrite and barite from the deposit to characterize the mineralization and to constrain its petrogenesis. The mineralization is hosted in quartz-chlorite veins associated with 2.5 Ga and 1.6 Ga granitoids. The mineralization is focused along the NW-SE trending Thanewasna brittle-ductile shear zone and comprises disseminated and vein-hosted Cu-sulfides, mainly chalcopyrite and pyrite intergrown with minor magnetite, hematite, and sulfide-free barite. The associated hydrothermal alteration is characterized by pervasive potassic-sodic alteration and chloritization. Calcite and sulfide-bearing barite veins postdate the Fe-oxide and Cu-sulfide ores. At least two generations of magnetite, hematite, and pyrite were identified based on their textural and trace element characteristics.Texturally early magnetite (Mag-I) displays oxy-exsolution of ilmenite and is of magmatic origin, representing the pre-mineralization igneous assemblage of the host rocks. Texturally later magnetite (Mag-II) is of hydrothermal origin and replaces Mag-I. It has high Co and Mg concentrations and shows dissolution and re-precipitation texture as well as evidence for high-temperature annealing. Martitisation of Mag-I and II associated with chloritization and Cu-Au mineralization produced hematite.The δ34SVCDT of syn-mineralization pyrite and chalcopyrite (−0.77‰ to −4.28‰) is suggestive of magmatic sources for the sulfur. Post-mineralization barite veins have δ34SVCDT between +10.31‰ and +17.55‰ which indicate that the sulfur was derived from seawater sulfate without going through an intermediate stage of reduction. Variation in the sulfur isotopic compositions of sulfide and sulfate was the result of dilution and cooling of the metalliferous fluid after interaction with meteoric fluids, which triggered the deposition of Cu ± Au along structural weak planes.The widespread presence of iron-rich breccias, association with crustal-scale shear zone, pervasive K-Na alteration, chloritic and advanced argillic alteration, the involvement of magmatic and non-magmatic fluid and Cu-Fe-Au-Ag-Ba-REE metal association are all suggestive of IOCG-style mineralization at Thanewasna. This supported by the Ti, Al + Mn, Ti + V concentrations and Ti/V, Ni/Cr, Ni/(Cr + Mn) ratios of Mag-II and hematite. The Co/Ni ratios of pyrite further supports a hydrothermal origin of the deposit, unrelated to skarns or copper porphyry, having similarity with known IOCG deposits. The identification of IOCG-type deposits in the Thanewasna region gives a boost to deeper sub-surface exploration in this belt as well as in similar geological setting elsewhere.

Current-voltage characteristics of Cu2ZnSnS4 absorber layer for energy harvesting devices

Environment friendly Copper-Zinc-Tin-Sulphide (CZTS)/Cadmium sulphide (CdS) thin film solar cells have been fabricated by sequential vacuum thermal evaporation technique. The developed CZTS films having the thickness of 1μm from layer by layer deposition of Cu: ZnS: Sn precursors having various compositional ratios (2:1:1, 2:1.5:1 and 2:2:1). Structural and morphological information of CZTS films were analyzed by XRD, Raman and SEM. The structural analysis showed increase with thickness and grain size increases whereas strain and dislocation density decreases. UV–vis absorption studies revealed that CZTS thin films have an optical band gap around 1.5 eV and it shows a large absorption coefficient (>104 cm−1). Four probe and Hall measurements indicate that CZTS thin film has the resistivity from 1.5–2.96 Ω-cm and the hole concentration from the value 9.1 × 1016–2.09 × 1018 N (cm−3). The deposited film CZTS were annealed at 500°C, to avoid forming binary compounds. Thin film solar cell has the structure of ITO/Mo/CZTS/CdS/i-ZnO/Al-grid/ITO exhibits the photovoltaic conversion efficiency of 5.6% under Air Mass (AM) 1.5 conditions and its photovoltaic performances were examined. This approach is favoured due to cell efficiency has a very large influence on the acceptable manufacturing cost of a PV module.

Electrodeposited Cu thin layers as low cost and effective underlayers for Cu2O photocathodes in photoelectrochemical water electrolysis

Cu2O is one of the most studied semiconductors for photocathodes in photoelectrochemical water splitting (PEC-WS). Its low stability is counterbalanced by good activity, provided that a suitable underlayer/support is used. While Cu2O is mostly studied on Au underlayers, this paper proposes Cu(0) as a low-cost, easy to prepare and highly efficient alternative. Cu and Cu2O can be electrodeposited from the same bath, thus allowing in principle to tune the final material’s physico-chemical properties with high precision with a scalable method. Electrodes and photoelectrodes are studied by means of electrochemical methods (cyclic voltammetry, Pb underpotential deposition) and by ex-situ X-ray absorption spectroscopy (XAS). While the potential applied for the deposition of Cu has no influence on the bulk structure and on the photocurrent displayed by the semiconductor, it plays a role on the dark currents, making this strategy promising for improving the material’s stability. Au/Cu2O and Cu/Cu2O show similar performances, the latter having clear advantages in view of future use in practical applications. The influence of Cu underlayer thickness was also evaluated in terms of obtained photocurrent.

High-performance carbon fiber/gold/copper composite wires for lightweight electrical cables

In this study, we synthesized high-performance Carbon Fiber/ Gold/ Copper (CF/Au/Cu) composite wires by using a 2-step deposition method via sputtering and electrodeposition. After Au was sputtered on PAN-based CFs as a pre-treatment, the wettability and surface reactivity of the CFs were improved, resulting in a homogeneous deposition of Cu on their surface. At different Cu electrodeposition time, the resulting CF/Au/Cu composite wires could possess a high strength of up to 3.27 GPa (∼ 10 times stronger than copper wires) while their electrical conductivity could be as high as 4.4 ×105 S/cm (∼ 75 % of that for copper). More importantly, since the composite wires were lightweight (up to 70 % lower than Cu mass density), they are a promising candidate to substitute conventional heavy metal wires in the future electrical applications.

Strong, lightweight, and highly conductive CNT/Au/Cu wires from sputtering and electroplating methods

In this study, we present a 2-step deposition method via sputtering and electroplating that uses carbon nanotube (CNT) wires synthesized from a wet-spinning technique to produce high-performance CNT/Au/Cu composite wires. After the Au sputtering pre-treatment, the deposition of Cu on the CNT wires was found to be much more homogeneous due to improved wettability and reactivity of the wire surface. At different electrodeposition time, the mechanical strength of the CNT/Au/Cu composite wires could be as high as 0.74 GPa (∼ 2 times stronger than metal wires) while their electrical conductivity could reach 4.65 × 105 S/cm (∼ 80% of that for copper). More importantly, the CNT/Au/Cu composite wires with high CNT volume fraction are expected to be lightweight (up to 42% lower than Cu mass density), suggesting that our high-performance composite wires are a promising candidate to substitute conventional heavy metal wires in the future applications.

Preventing the Deactivation of Gold Cathodes During Electrocatalytic CO2 Reduction While Avoiding Gold Dissolution

The electrochemical reduction of CO2 on gold cathodes was investigated, and the major products were found to be CO, H2 and formate, which is consistent with existing literature. The Faradaic efficiency for CO production decreased from around 60 to 10% over the course of 4 h when the electrolysis was performed at – 5 mA cm–2 in 0.2 M KHCO3 saturated with CO2. This deactivation was accompanied by an increase in the selectivity of the cathode towards H2 and formate production, which is normally attributed to the deposition of metals from trace impurities in the electrolyte or surface-bound species formed during the reaction. In this case, the deactivation was found to be due to the deposition of Cu, Zn and possibly Fe from the electrolyte, with the presence of Fe strongly enhancing H2 production, the Cu deposition increasing the formate production rate and Zn enhancing both H2 and formate production. While the accumulation of these poisons can be prevented with periodic anodic treatments (using methods previously described in the literature), these treatments lead to significant gold dissolution, with up to 450 ppb of gold found in the electrolyte after 4 h of electrolysis, and thus is unsuitable for use in long-term CO2 reduction systems. This dissolution is expected to alter the surface structure and thus selectivity of the cathode. Therefore, alternative electrochemical cleaning protocols (periodic cyclic voltammetry, open-circuit and low anodic current treatments) were investigated as methods to remove these poisons without significant gold corrosion occurring. The best approach to prevent the deactivation of gold cathodes during CO2 reduction is to cycle the potential between − 0.5 and 0.5 V vs Ag|AgCl every 15 min during long-term electrolysis. It is also shown that simply interrupting the CO2 reduction process every 15 min with 4 min at open circuit can also partially prevent the deactivation of the CO2 reduction reaction as will short anodic current pulses.

Polarization-sensitive photoresponse of the CuSe/Se nanocomposite prepared by vacuum thermal deposition

We report on the generation of the polarization-sensitive photocurrent in the thin film of the CuSe/Se nanocomposite irradiated by femtosecond pulses of Ti:S laser. CuSe/Se bilayer consisting of nanocrystalline CuSe and amorphous Se films was obtained using successive deposition of Cu and Se on a glass substrate in the course of vacuum thermal evaporation. Synthesized bilayers were characterized using optical transmittance and Raman spectroscopy, optical, atomic force and scanning electron microscopy and X-ray diffractometry. It is demonstrated that in the longitudinal configuration, the photocurrent propagating along the plane of incidence is maximum for the p- and vanishes for the s-polarized excitation beam. In the transverse configuration, the photocurrent propagating perpendicular to the plane of incidence is an odd function of the polarization azimuth of the linearly polarized excitation beam and vanishes when it is either p- or s-polarized. We show that for an elliptically polarized excitation beam the polarity of the transverse photocurrent reverses when rotation direction of the electric field vector changes. Both longitudinal and transverse photocurrents are odd functions of the angle of incidence and can be explained in terms of the surface photogalvanic effect.

Electrochemical memristive devices based on submonolayer metal deposition

This paper explores the concept of an analog memristive device based on reversible electrochemical deposition and deplating of a submonolayer metal layer on a 108 Ω resistive bar. Initial feasibility experiments demonstrate a continuous resistance change by seven orders of magnitude during physical vapor deposition of Cu on TaNx/SOI, with the most promising range from 5.6 × 107 to 1.1 × 107 Ω/□ during a 0.64 monolayer Cu deposition. Cyclic electrochemical deposition and deplating of Cu on a metal seed on SiO2 in a 0.01M CuSO4/H2SO4 pH 1.4 solution demonstrates a reversible resistance variation with a minimum of 10 ± 1 discrete resistance states. These initial results are promising but also reveal a key materials challenge: the need for controlled and reversible electrochemical deposition/deplating of a submonolayer metal on the surface of a relatively high resistivity (≥10−2 Ω m) material.

Role of hydrazine in the enhanced growth of zinc sulfide thin films using chemical bath deposition for Cu(In,Ga)Se2 solar cell application

We investigated the hydrazine effect on the physical characteristics of zinc sulfide (ZnS) thin films on both the soda-lime glass substrate and the Cu(In,Ga)Se2 (CIGS) absorber layer as a function of its relative content rc with respect to ammonia as well as the deposition time td in the chemical bath deposition. As the rc varied from 0 to 1.39, all the deposited ZnS films using hydrazine as a secondary complexing agent showed nearly identical characteristics of amorphous structure with the composition of [S/(S + O)] ~ 0.32 and the direct energy bandgap of Eg = 3.54–3.75 eV. However, they exhibited a strong dependence of light transmission on the longer deposition times td (≥70 min), due to the enhancement of the areal density of in-plane grains. By applying the ZnS buffer on top of the CIGS, the heterojunction device showed the best solar cell performance with η = 12.03%, Voc = 0.549 V, Jsc = 32.92 mA/cm2, FF = 66.7% from the ZnS buffer grown at rc = 0.28 and td = 30 min. When compared to only ammonia, the relative hydrazine was found to play a key role in the deposition of ZnS to expedite the in-plane grain growth by 6 times accompanied both with a reduction of in-plane grain size and a denser packing density.