RF Sputtering Method Research Articles

Enhanced efficiency of mono-crystalline Si solar cells utilizing RF sputtered TiO2–Al2O3 blended anti-reflection coating for optimal sunlight transmission and energy conversion

Currently, surface reflection of incident sunrays over solar cells results in degradation of output performance of the solar cells. This can be sorted out using an antireflection coating. In this investigation, ARC materials such as Titanium dioxide (TiO2), Aluminium oxide (Al2O3) and blended TiO2– Al2O3 were utilized over the mono-crystalline Si (m-Si) solar cells. The ARCs for m-Si solar cell was coated using RF sputtering method. The optical, structural, electrical, I–V characteristics and temperature behavior of solar cell samples with coating and bare cells were studied. The elemental analysis was carried out using X-ray diffraction (XRD) method. The morphological study was conducted using High Resolution Transmission Electron Microscopy (HR-TEM) and Atomic Force Microscope (AFM). The electrical resistivity was measured in dark at room temperature using four-point probe technique. Optical characteristics was determined using UV–visible spectroscopy. It was discovered that the TiO2– Al2O3blend coated cell (I3) shows great performance than the other coatings. I3 solar cell demonstrated high power conversion efficiency (PCE) of 19.42 % and 20.16 %, when exposed to direct sunlight and neodymium radiation in both open and controlled environments. The findings indicate that TiO2– Al2O3blends are a suitable material for ARC applications, since they effectively reduce the incident photons scattering.

Development of ZnO and Si semiconductor-based ultraviolet photodetectors enhanced by laser-ablated silver nanoparticles

The present study employs a cost-effective laser ablation technique in combination with the RF sputtering method to successfully synthesize silver nanoparticles encapsulated by zinc oxide on a silicon (Si) substrate. This synthesis approach aims to enhance the efficiency of photodetector devices while concurrently reducing material expenses, thereby promoting advancements in photodetector applications. The incorporation of various plasmonic nanoparticles (NPs) into the photodetector's architecture is demonstrated as a means to substantially improve the photoresponse of UV photodetectors. Three distinct samples, denoted as AgNPs/Si, AgNPs/ZnO/Si, and ZnO/AgNPs/Si, underwent comprehensive analysis and characterization of their morphological attributes, crystal structures, elemental composition, and optical properties. The UV photodetection efficacy of these samples was evaluated by subjecting them to 385 nm UV light at different bias voltages. The current-voltage (I-V) characteristics of the ZnO/AgNPs/Si photodetector revealed significantly enhanced conductivity in comparison to the AgNPs/Si and AgNPs/ZnO/Si counterparts. Remarkably, the ZnO/AgNPs/Si photodetector exhibited the highest responsivity value of 132 A/W, accompanied by quantum efficiency of 429.88, sensitivity of 31,400%, gain of 315, detectivity of 18 × 1010 Jones, and a noise equivalent power (NEP) of 0.556 × 10–13 W. These findings underscore the efficacy of our innovative broadband photodetector, highlighting its potential for practical implementation. This research offers valuable insights into the enhancement of photodetector performance and its applicability in real-world scenarios.

(Invited) Nickel Nanoparticles Modified Carbon Film Electrodes for Detection of Sugars

Metal nanoparticles such as Pt, Au, Ni and Cu have been employed to detect various analytes including hydrogen peroxide, alcohol and sugar. Among these metal nanoparticles, Ni and Cu nanoparticles show excellent electrocatalytic activity for oxidizing sugars in alkaline solution. We employed co-sputtering and plating technique to fabricate nanostructured electrodes for enhancing electrocatalytic activity for oxidation of sugars. First example is a metal hererodimer modified carbon film electrodes. The metal nanoparticles embedded carbon film electrodes was fabricated by unbalanced magnetron (UBM) sputtering and then plated different metal nanoparticles selectively only on the embedded metal nanoparticles by utilizing overpotential difference between carbon and metal nanoparticles surfaces. Using this technique, various combinations of metals are available to fabricate vertically oriented heterodimers embedded in the carbon films. In fact, we succeeded to fabricated Ni(upper)@Pd(lower), Pt@Pd, Au@Pd, Ni@Au, Pt@Au and Pd@Au heterodimers partially embedded in the carbon film. Among these heterodimers, Ni@Pd heterodimer embedded carbon film electrode shows much higher redox reaction of Ni(OH)2 covered on the Ni nanoparticles surface compared with that on the Ni nanoparticles without Pd. The NiOOH formed by electrochemical oxidation shows much higher electrocatalytic activity for glucose compared with that formed on Ni nanoparticles modified carbon film electrode. Also, the Ni@Pd heterodimers are mechanically very stable and most of the heterodimers remained on the surface after ultrasonication treatment because surface Ni nanoparticles attached strongly to Pd nanoparticles embedded in the carbon film. In contrast, almost all Ni nanoparticles deposited on pure carbon film were detached from carbon surface after ultrasonication. The second example is a nitrogen terminated carbon film modified with Ni nanoparticles by plating. Carbon films were fabricated by UBM or RF sputtering methods and then introduced nitrogen containing functional groups. Then Ni nanoparticles were deposited by plating. The supporting effect of a N-doped carbon film induced superior crystallinity in plated Ni@Ni(OH)2 nanoparticles, which was confirmed by HAADF-STEM-EDS. This realized a much higher regeneration rate of catalytic sites (NiOOH) , leading to higher oxidation current for maltopentaose, which is well known oligosaccharide. Also, the overpotential of maltopentaose oxidation decreased significantly due to the effect of the electrostatic interaction between Ni nanoparticles and maltopentaose in the alkaline solution at pH 12.7. We also studied dependence of nitrogen concentration in the carbon film on regeneration rate of NiOOH and glucose oxidation. Both regeneration rate and electrocatalytic current of glucose oxidation increased with increasing nitrogen concentration from 0 to 3.1 %. With optimized nitrogen concentration, we could measure glucose from 25 µM to 400 µM. The enhanced activity of Ni nanoparticles could be advantageous to develop enzyme free biosensor or fuel cells using organic compounds such as sugars and oligosaccharides.[1]S. Shiba, A. Koike, S. Takahashi, D. Kato, T. Kamata and O. Niwa, ACS Nano, 16, 10589-10599 (2022).[2] S. Shiba, S. Ohta, K. Ohtani, S. Takahashi, D. Kato and O. Niwa, RSC Advances, 11, 13311-13315 (2021).

IoT-enabled surface-active Pd-anchored metal oxide chemiresistor for H2S gas detection

The Internet of Things (IoT) has a crucial role in advancing various fields such as Industry 4.0, Big Data, and Machine-to-Machine technologies. All systems continuously gather information on various parameters such as temperature, speed, pressure, health data, environmental conditions, and consumption. Considering this, we've developed a novel fabrication method for H2S gas sensor prototypes. These sensors are based on noble metal-functionalized on metal oxide semiconductor (MOS) chemiresistors. The fabrication process involved growing CuCrO2 sensing thin film on SiO2/Si substrates using the RF sputtering method. Subsequently, Pd nanoparticles, known for their excellent gas-sensing catalyst properties, were functionalized onto the CuCrO2 films using DC sputtering with varying sputtering times of 3, 6, 9, and 12 s. Nanorice morphology boosts gas absorption, capturing more target molecules. A 9 s Pd sputtering time greatly improved H2S sensing over other gases. CuCrO2 film with Pd showed the highest 72.3% response to 50 ppm H2S, detecting down to 0.5 ppm. These results were achieved at the optimal working temperature of 150 °C. After optimizing parameters, we transferred the technology to develop a sensor module for the prototype with IoT integration. The prototype sensor connects to NODEMCU-ESP8266 Wi-Fi, which links to a smartphone through a mobile hotspot.

Structural and magnetic properties of YIG thin films deposited by pulsed laser deposition and RF magnetron sputtering technique

Yttrium iron garnet (YIG) has been extensively explored for its potential avenues in spintronic applications. A majority of these studies employ thin films grown by PLD at high substrate temperature, which generally leads to an interfacial dead layer with cations interdiffusion hindering their technological implications. In this communication, we report the growth of YIG thin films at room temperature by PLD and RF sputtering techniques. Detailed structural investigation confirms the thin films’ single-phase growth and epitaxial nature. We have a further detailed investigation of magnetic properties by dc magnetization, magneto-optical Kerr effect and FMR techniques. Although our thin films exhibit a comparatively lower magnetic performance in terms of saturation magnetization and damping constant, we have obtained a significantly lower interfacial dead layer thickness of ∼1 nm, which is quite promising for spin transport applications. The present study, therefore, calls for future studies for simultaneous optimization of magnetic performance and interfacial dead layer with room temperature grown YIG thin films by both PLD and RF sputtering methods.

Copper Nitride: A Versatile Semiconductor with Great Potential for Next-Generation Photovoltaics

Copper nitride (Cu3N) has gained significant attention recently due to its potential in several scientific and technological applications. This study focuses on using Cu3N as a solar absorber in photovoltaic technology. Cu3N thin films were deposited on glass substrates and silicon wafers via radio-frequency magnetron sputtering at different nitrogen flow ratios with total pressures ranging from 1.0 to 5.0 Pa. The thin films’ structural, morphology, and chemical properties were determined using XRD, Raman, AFM, and SEM/EDS techniques. The results revealed that the Cu3N films exhibited a polycrystalline structure, with the preferred orientation varying from 100 to 111 depending on the working pressure employed. Raman spectroscopy confirmed the presence of Cu-N bonds in characteristic peaks observed in the 618–627 cm−1 range, while SEM and AFM images confirmed the presence of uniform and smooth surface morphologies. The optical properties of the films were investigated using UV-VIS-NIR spectroscopy and photothermal deflection spectroscopy (PDS). The obtained band gap, refractive index, and Urbach energy values demonstrated promising optical properties for Cu3N films, indicating their potential as solar absorbers in photovoltaic technology. This study highlights the favourable properties of Cu3N films deposited using the RF sputtering method, paving the way for their implementation in thin-film photovoltaic technologies. These findings contribute to the progress and optimisation of Cu3N-based materials for efficient solar energy conversion.

High self-powered UV–Visible photoresponse in ZnO/CuO heterostructure photodetectors, the influence of ZnO window layer thickness

In this study, we have fabricated ZnO/CuO heterostructure photodiodes on FTO substrate using the RF-sputtering method and investigated the influence of the ZnO thickness (390 and 470 nm) on their photoresponse in the wide range of UV to red wavelengths. The layers were characterized by FESEM, XRD, Raman, PL, and UV–Vis. Spectra, also I–V, I–V–T (295–340 K), and I-t in the dark and under illumination. We found: (1) the constituent layers have a polycrystalline nature, monoclinic phases for CuO and wurtzite phase for ZnO layers; (2) in addition to rectifying behavior, the I–V–T analysis confirmed that the current mechanism of these junctions follows the recombination model; (3) both samples have the potential of photovoltaic properties with self-powered ability; (4) sample with thinner ZnO layer has the highest photoresponse ratio (ILight/IDark) of 5.5 × 104–2.6 × 103 through UV to red light illumination and fast response time of 45–50 ms.

Electrodeposited NiFe2O4/Cu2O heterostructure thin films with enhanced photocurrent generation

In comparison with single-phase materials, heterostructures have been known for superior water splitting applications. In this study, Cu2O and NiFe2O4 are chosen to fabricate thin film heterostructures. Cu2O is electrodeposited at 60 °C for 5 min on ITO-coated glass substrates using three-electrode system. After deposition, the phase formation is confirmed using powder x-ray diffraction studies. The NiFe2O4 (NFO) thin films are deposited using RF sputtering method at room temperature for 2 h on Cu2O/ITO substrates to obtain NFO/Cu2O/ITO Type-II heterostructure. The scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) cross-sectional images show that the thickness of NFO layer is 120 nm and Cu2O layer is 1.5 µm. The photocurrent density of Cu2O on ITO is 0.08 ± 0.002 mA/cm2, and it increased to 0.12 ± 0.002 mA/cm2 after adding NFO layer on Cu2O film due to Type-II heterojunction formation.

The effect of coated diamond-like carbon thin films on polymer tooth based denture: Micro-morphology and fractal feature studies

To consider improving the micromorphology study of dentures combined with biocompatibility in recent years, we study hybrid organic–inorganic materials and diamond-like carbon coated on tooth-based dentures by the sol–gel and the RF sputtering method, respectively. Afterward, the effect of such material coating on the surface roughness and surface topography of dentures was evaluated. Aimed at this, 3D atomic force microscope images were analyzed via MountainsMap® Premium software, which divided the surface into peaks and pits through the watershed segmentation algorithm. This method made motif analysis possible by detecting the surface dimensions, curvature, volume, perimeters, shape, structure, etc., and the obtained statistics indicate interesting results for the regular and irregular topography and the surface of the prepared samples. In addition, the energy-dispersive x-ray spectrum illustrates the existence of N, C, O, Na, and Si in all samples, with the maximum value of C in the diamond-like carbon coated sample, which is because of the highest value of carbon in diamond-like carbon. Scanning electron microscope images also present a series of grooves on the surface with small randomly oriented cracks. The linear interpolation type shows that the surface of diamond-like carbon coated on the hybrid-control sample has the most irregular topography while the most regular topography was found in the hybrid coated control sample.

Visible light active Fe2O3/SnS heterojunction decorated with graphene oxide layer for improved photoelectrochemical performance

Tin monosulfide, also known as SnS, is a significant IV-VI group semiconductor that has acquired considerable emphasis owing to its good absorption in visible range. In the present work, nanostructured thin films of pure SnS, Fe2O3, and Fe2O3/SnS heterojunction were synthesized using cost effective thermal evaporation and Rf sputtering method, respectively. Furthermore, to enhance the sample's photoelectrochemical activity, a homogenous thin film of graphene oxide (GO) is coated on Fe2O3/SnS heterojunction sample. All samples were well characterized and their photoelectrochemical response was investigated. The maximum photocurrent density was observed for Fe2O3/SnS/GO heterojunction i.e. 1.0 ​mA/cm2 which is much higher than pure SnS (0.3 ​mA/cm2) and Fe2O3 (0.02 ​mA/cm2) at 0.95 ​V vs. Ag/AgCl. The role of graphene layer is being examined for the improved photoresponse. Remarkable photoresponse and stability of the Fe2O3/SnS/GO heterojunction sample may be attributed to better charge separation at the interfacial junction of SnS and Fe2O3 and excellent electron density of GO layer.

ZnO, Cu-doped ZnO, Al-doped ZnO and Cu-Al doped ZnO thin films: Advanced micro-morphology, crystalline structures and optical properties

The thin film coatings composed of: undoped ZnO film, ZnO doped with Al, ZnO doped with Cu, and ZnO simultaneously doped with Al and Cu (co-doping) were separately deposited on quartz substrates using RF sputtering method with different targets. The advanced fractal features, crystalline structure and optical properties of sputtered samples were investigated by atomic force microscopy (AFM), X‐ray diffraction (XRD) and UV–vis spectroscopy. Microstructural studies revealed homogeneously granular structure of ZnO layer and axially oriented granular structure of AZO thin film.The transmission spectra of undoped, mono-doped and co-doped ZnO thin films were measured revealing relatively large transmittance of more than 80 % for un-doped and co-doped samples and less than that value for mono-doped thin films in both visible and infrared regions. CAZO thin film was found the most transparent thin film in the visible area being a prerequisite for good TCO. Analysis of absorption coefficients demonstrated that excitonic effects are invisible in mono-doped and co-doped samples. Also, PL spectra show that in these samples there are very high densities of free carriers and presence of impurities, which is important for conductivity of thin films as well as their optical applications. The optical band gap of ZnO thin films decreases by Cu doping from 3.12 eV to 3.09 eV and increases by Al doping to 4.30 eV, but remains exactly between those values in terms of co-doped sample (3.75 eV).

Comparative study of UV-ZnO NRs photodetectors based on seeded porous silicon by RF-sputtering and drop-casting methods

Comparative study of UV-ZnO NRs photodetectors based on seeded porous silicon by RF-sputtering and drop-casting methods

Safety-Enhanced Polyethylene Separator with Thermally Conductive Ultra-Thin Ceramic Coating Layer for Advanced Libs

Lithium-ion batteries (LIBs) are widely used from small electronic devices to large-format electric vehicles and energy storage systems. However, as the energy density of LIBs increases, ensuring safety becomes more important to battery manufacturer. [1] As a result, battery engineers are reluctant to use bare polyethylene separators without the ceramic coating layer, which is generally fabricated from the slurry containing ceramic particles, binder, and solvent. Thus, the ceramic-coated separator (CCS) becomes a must-have item for state-of-the-art LIBs. However, since an additional ceramic layer not only reduces the energy density of LIBs, but also increases the cell resistance, there are previous works to reduce those resistive ceramic layers without compromising the thermal or mechanical properties of CCSs. [2] The key process they utilized was the deposition, which can coat the SiO2, Al2O3, or TiO2 ceramic layers of tens of nanometer on the surface of separators. [3,4,5,6] Thus, without ceramic coating layer of a few micrometers, they could show both improved electrolyte affinity and thermal stability comparable to the conventional slurry-based CCSs. However, except for oxide-based ceramics, other ceramics like nitride, which has a good thermal conductivity, have not been tried for this ultra-thin ceramic coating layers.Thus, herein, we attempt to deposit nitride on polyethylene separators using RF sputtering method. After the CCS was prepared, its physical properties such as thickness, mass per area, permeability, and morphological change were evaluated with a control CCS with Al2O3 layer. Also, not only thermal stability but also thermal conductivity was compared between nitride- and oxide-based CCSs. Furthermore, their electrochemical properties such as cyclability and rate capability were also investigated with large-area pouch-type full cells. Through these comparative study, pros and cons of ultra-thin nitride layer would be reported for advanced LIBs.[1] John B. Goodenough et al., J. Am. Chem. Soc. 2013, 135, 1167−1176.[2] Karun Kumar Jana et al., ChemBioEng Reviews, 2018, 5, 346-371[3] Taejoo Lee et al., Macromolecular Research, 2014, 22, 1190–1195[4] Min Kim et al., Journal of Power Sources, 212, 2012, 22-27 [5] Yoon Seok Jung et al., Adv. Energy Mater. 2012, 2, 1022–1027[6] Kun Peng et al., RSC Adv., 2015, 5, 81468

Investigation of dielectric and electric behavior of MgTiO3 and Ba0.5Sr0.5TiO3 bilayer films by RF sputtering method

The structural, microstructural, electrical, and dielectric properties of MgTiO3 (MTO)/ Ba0.5Sr0.5TiO3 (BST) bi-layer structures grown by reactive RF magnetron sputtering have been reported. The films exhibited polycrystalline nature and the stacking of BST on MTO (BST/MTO) exhibited better crystallinity than that of MTO stacking on BST(MTO/BST). The RMS roughness for BST/MTO and MTO/BST is found to be 1.82 nm and 49.2 nm, respectively. The dielectric constant (εr, ∼27.3) and loss tangent (tanδ, ∼10−2) at 100 kHz for BST/MTO are found to be intermediate to BST and MTO monolayer responses. The anomaly observed in dielectric response (εr, ∼323.2 and tanδ, ∼10−2) for MTO/BST can be attributed to the generation of charge carriers in the interfaces of individual layers. The relation between electrically active regions with the observed electrical response is studied by impedance spectroscopy. The leakage in MTO/BST (10−2 A/cm2 at 100 kV/cm) bilayer is higher than that of BST/MTO (10−4A/cm2 at 100 kV/cm) bilayer and Schottky emission along with Space-charge limited current contribute to the leakage current. Both MTO/BST and BST/MTO films exhibited tunable dielectric responses. These findings of this report provide prospective insight into the design of multilayer structured smart materials.11MTO and BST bilayer films

Influence of gamma radiation on optical, structural and surface morphological properties of WO3 thin films grown by RF sputtering

In the present study, tungsten oxide (WO3) thin films were grown on glass and silicon substrates using RF sputtering method and thin films were annealed at 550 °C. The prepared WO3 thin films were exposed through gamma irradiation by varying doses at 100, 200, 300, 400 and 500 kGy. The modification in optical, structural, morphological and chemical properties of WO3 thin films before and after gamma irradiation doses were observed from UV-Vis, Photoluminescence (PL) and Raman spectroscopy, Fourier Transform spectroscopy (FTIR), Atomic Force Microscopy (AFM), X-ray diffraction (XRD), Rutherford backscattering (RBS) and X-ray photoelectron spectroscopy (XPS). The grain size after gamma irradiation reduced from 6.56 nm to 3.40 nm. The Raman spectroscopy reveals the monoclinic phase of tungsten oxide thin films after gamma irradiation. XRD pattern shows the variation in crystallite size from 7.2 nm to 33.8 nm. The optical band gap of pristine and gamma irradiated thin films was observed from UV-Vis spectroscopy. The functional groups were confirmed by FTIR spectroscopy. PL emission peaks were observed at 415 nm and 475 nm for pristine and gamma irradiated thin films at excitation wavelength of 380 nm. The XPS study reveals the presence of W and O atoms in pristine and gamma irradiated WO3 thin films.

Advanced microstructure, morphology and CO gas sensor properties of Cu/Ni bilayers at nanoscale

In this study, we investigated the morphology of synthesized Cu/Ni nanoparticles in trace of carbon sources by the co-deposition process of RF sputtering and RF-PECVD methods and localized surface plasmon resonance of CO gas sensing of Cu/Ni nanoparticles. The surface morphology was studied by analyzing 3D micrographs of atomic force microscopy using image processing techniques and fractal/multifractal analyses. The MountainsMap® Premium software with the two-way ANOVA (Variance analysis) and least-significant differences tests were used for statistical analysis. The surface nano-patterns have a local and global particular distribution. Experimental and simulated Rutherford backscattering spectra confirm the quality of nanoparticles. Then, prepared samples were exposed to CO gas flue to study their gas sensor application using the localized surface plasmon resonance method. Increasing the Ni layer over Cu one shows an interesting result in both morphology and gas sensing sides. Advanced stereometric analyses for the surface topography of thin films in conjunction with Rutherford backscattering spectrometry and Spectroscopic analysis make a unique study in the field.

Dependence of magnetic properties in superparamagnetic Co-granular thin films on deposition rate and effectiveness of a new pulsed DC reactive sputtering method for film fabrication with high deposition rate.

The superparamagnetic thin films with a granular structure show a characteristic magnetization curve. In this study, Co-Al2O3 granular thin films were fabricated by the sputtering method with normal DC source for Co deposition, RF source for Al2O3 deposition, and pulsed DC reactive sputtering were used for fabrication of non-magnetic matrix of oxide or nitride of Al or Si. As a result, Co-Al2O3 superparamagnetic thin films with high magnetization could be obtained with high deposition rate. Very high deposition rate was obtained for fabrication of oxide or nitride films of Al or Si using the pulsed DC reactive sputtering method. This deposition rate was 5 times larger than RF sputtering method. It is expected that a sputtering method with DC source for Co deposition and pulsed DC source for matrix deposition will be effective to realize very high magnetization in the superparamagnetic granular thin films.

Electrical transport properties of thick and thin Ta-doped SnO2 films

Ta-doped SnO2 films with high conductivity and high optical transparency have been successfully fabricated using the rf-sputtering method, and their electrical transport properties have been investigated. All films reveal degenerate semiconductor (metal) characteristics in electrical transport properties. For the thick films (t∼1μm with t being the thickness) deposited in pure argon, the electron–phonon scattering alone cannot explain the temperature-dependent behaviors of resistivity, the interference effect between electron–phonon and electron–impurity scattering should be considered. For t≲36 nm films, both the conductivity and the Hall coefficient show a linear relation with the logarithm of temperature (ln⁡T) from ∼100 K down to liquid helium temperature. The ln⁡T behaviors of conductivity and Hall coefficient cannot be explained by the Altshuler-Aronov type electron–electron interaction effect but can be quantitatively interpreted by the electron–electron interaction effects in the presence of granularity. Our results not only provide strong support for the theoretical results on the electron–phonon–impurity interference effect, but also confirm the validity of the theoretical predictions of charge transport in granular metals in a strong coupling regime.

Optoelectrical impact of alternative window layer composition in CdTe thin film solar cells performance

This study investigates the integrability of different alternatives of cadmium sulfide (CdS), namely, oxygenated cadmium sulfide (CdS:O) and cadmium zinc sulfide (CdZnS) as the potential window layers in CdTe thin film solar cells using SCAPS-1D and experimental fabrication. The performance parameters such as open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF), conversion efficiency (η), and quantum efficiency (QE) have been examined for cells with different carrier concentration and series resistance (Rs) of window layer materials. Calculation results shows that the incorporation of oxygen (CdS:O) with series resistance (Rs ≤ 1E−1 Ω.cm2) and minimum carrier concentration of 1016 cm−3 contributes in optimum band alignment that enhances photo-current collection from both short and long wavelength regions compared to baseline CdS/CdTe solar cell. Moreover, the performance of the proposed cells has been improved in terms of QE, Jsc, Voc, η, and FF upon insertion of novel CdZnS layer. However, carrier recombination increases the saturation current density for CdZnS resulting in unstable performance. Consequently, upon insertion of CdS:O window layer, conversion efficiency enhancement is observed with Jsc (29.10 mA.cm−2), Voc (0.889 V) and FF (70.39%). The proposed window materials are deposited using RF-sputtering method and the experimental results are incorporated in simulation to validate the findings.

Fabrication and characterization of ITO/ZnO/anthraquinone solid dye-sensitized solar cells

The use of natural dyes as sensitizers in organic solar cells is getting more interest due to its green nature, nontoxicity, low cost and ecofriendly materials. In this paper, two anthraquinone/zinc oxide-based dye-sensitized solar cells (DSSCs) were prepared by a simple and low cost method. The anthraquinone was extracted from Aloe-vera plant and was deposited as a thin film to study its structural and optical properties. ZnO nanoparticles and nanorods were prepared by the RF sputtering and electrodeposition methods, respectively. The Glass/ITO/ZnO/anthraquinone/Al structure exhibited a promising photovoltaic activity.