Current Density-voltage Characteristics Research Articles

Performance of dye-sensitized solar cells extracted dye from wood apple leaves

In this work, wood apple leaves dye has been extracted, characterized, and examined as a potential photosensitizer for dye-sensitized solar cells (DSSCs). The dye was extracted in an ethanolic medium from the fresh wood apple leaves and characterized using thin-layer chromatography (TLC), ultraviolet-visible (UV-Vis), and Fourier transform infrared (FTIR) spectroscopy. The current density-voltage (J–V) characteristics measurements were performed on the two assembled DSSCs for 1–22 days using fresh and seven days old extracted dye. The characterization results revealed that the extracted dye mainly contains the compound of carotenoids (neoxanthin), chlorophyll a, chlorophyll b, and their derivative (pheophytin) with various functional groups. The J–V characteristics of DSSCs indicate that an open-circuit voltage and short circuit current density radically decrease with increasing time, thus degrading the efficiency of cells. A degraded DSSCs suffered from high defect recombination may be induced by Mg ions migrating from chlorophyll dye into DSSC. Therefore, the extracted dye may be used for energy harvesting from the wood apple leaves.

Solid oxide cells with cermet of silver and gadolinium-doped-ceria symmetrical electrodes for high-performance power generation and water electrolysis

A cermet of silver and gadolinium-doped-ceria (Ag-GDC) is investigated as novel symmetrical electrode material for (ZrO2)0.92(Y2O3)0.08 (YSZ) electrolyte-supported solid oxide cells (SOCs) operated in fuel cell (SOFC) and electrolysis (SOEC) modes. The electrochemical performances are evaluated by measuring the current density-voltage characteristics and impedance spectra of the SOCs. The activity of hydrogen and air electrodes is investigated by recording overpotential versus current density in symmetrical electrode cells, respectively in hydrogen and air, using a three-electrode method. Conventional hydrogen electrode, Ni-YSZ, and oxygen electrode, LSCF (La0.6Sr0.4Co0.2Fe0.8O3-δ)-GDC, are tested as comparison. The results show that, as an oxygen electrode, Ag-GDC is more active than LSCF-GDC in catalyzing both oxygen reduction reaction (ORR) in an SOFC and oxygen evolution reaction (OER) in an SOEC. As a hydrogen electrode, Ag-GDC is more active than Ni-YSZ in catalyzing hydrogen oxidation reaction (HOR) in an SOFC and hydrogen evolution reaction (HER) in an SOEC, especially in high steam concentration. An SOC with symmetrical Ag-GDC electrodes operated in a fuel cell mode, with 3% H2O humidified H2 as the fuel, displays a peak power density of 395 mWcm−2 at 800 °C. Its polarization resistance at open circuit voltage is 0.21 Ω cm2. Ag-GDC electrode can be operated even at pure steam. An SOEC operated for electrolyzing 100% H2O, the current density reaches 720 mA cm−2 under 1.3 V at 800 °C.

Ethylcellulose‐Encapsulated Inorganic Lead Halide Perovskite Nanoparticles for Printing and Optoelectronic Applications

AbstractInorganic lead halide perovskite nanoparticles (NPs) have attracted attention for next‐generation optoelectronics and anti‐counterfeiting applications. The fully inorganic NPs get degraded in polar solvents resulting in poor stability. These also tend to degrade under exposure to high temperatures resulting in obstacles to application in reliable anti‐counterfeiting and optoelectronics applications. The encapsulation of perovskite NPs with ethyl cellulose (EC) as a polymer matrix to overcome these obstacles is explored using a facile solution blending technique followed by ultra‐sonication and characterization. These NPs demonstrate enhanced photoluminescence (PL) intensity, improved color clarity, and considerable stability. Along with organic binders, they can be used in developing printable ink for making patterns. A logo coated with CsPbBr3 + EC and CsPbBr1.5 I1.5 + EC exposed in normal light and UV light (365 nm) shows a clear image that becomes blue‐green and yellow color. Additionally, the effect of light on the current density–voltage characteristics of the size‐dependent encapsulated NPs shows that photocurrent has dramatically improved over 5.14 times in CsPbBr3 + EC and 1.68 times in CsPbBr1.5 I1.5 + EC compared to that of pristine one. These results demonstrate its potential uses for several applications such as luminescent printing applications, sensors, and optoelectronic applications.

Near Unity Absorbance and Photovoltaic Properties of TMDC/Gold Heterojunction for Solar Cell Application

In this paper, near unity broadband absorption of Van der Waals semiconductors on a metallic substrate, and their photovoltaic performances in the visible spectrum are simulated. Ultrathin layered semiconductors such as Molybdenum disulfide (MoS2), Tungsten disulfide (WS2), Molybdenum di-selenide (MoSe2), Tungsten di-selenide (WSe2), Molybdenum ditelluride (MoTe2), and Tungsten ditelluride (WTe2) can create strong interference by damping optical mode in their multilayer form and increase light absorption at their heterojunctions with noble metals. From our simulation, it is observed that this absorbance can reach up to 94% when the semiconductors are placed on a gold substrate. The optimum thickness of these semiconductors in their heterostructures with gold is analyzed to create resonant absorption to generate the maximum amount of current density. The power conversion efficiency of the designed Schottky junction solar cells is calculated from their current density vs bias voltage characteristics that ranges from 1.57% to 6.80%. Moreover, the absorption coefficient, dark current characteristic, electric field intensity distribution in the device, and carrier generation rate during light illumination are presented with a view to characterizing and comparing among the parameters of TMDC based nanoscale solar cell.

Effect of PVK mixed TAPC as hole transport layers on device performance of red quantum-dot light-emitting diodes

A series of red quantum-dot light-emitting diodes (QLEDs) are developed using poly(9-vinlycarbazole) (PVK) mixed 4,4′-Cyclohexylidenebis [N, N-bis(4-methylphenyl) benzenamine] (TAPC) as hole transport layer (HTL) by all-solution processing. The current density-voltage characteristics of carrier-only devices with emissive layer (EML) shows that the PVK: TAPC composite HTL exhibits the increase of current density at the same voltage with increasing the mixing concentration of TAPC. And the hole and electron currents are almost identical as the mixing concentration of TAPC is equal to 20%. The corresponding red QLED achieves the highest performance with a maximum luminance of 289 490 cd/m2, a maximum CE of 26.8 cd/A, a maximum EQE of 17.9% and a narrow full width at half-maximum (FWHM, 26 nm). The T50 lifetime is up to 65 min, which is more than 8 times longer than that of QLED with PVK as HTL at an initial luminance of 100 000 cd/m2. Furthermore, the efficiency roll-off is significantly reduced in the developed QLEDs. For instance, even at a very high brightness over 50 000 cd/m2, the QLEDs can still maintain a high CE of 26.6 cd/A and an EQE of 17.4%. The results show that the PVK: TAPC composite HTL builds energy level cascade to some degree and improve the hole transport capacity, leading to better charge carrier transfer balance. Consequently, the device performance is promoted.

Current-voltage hysteresis reduction of CH3NH3PbI3 planar perovskite solar cell by multi-layer absorber

In this paper, we present two structures with two and three-layer absorber to reduce the current density-voltage (J-V) characteristics hysteresis of the planar perovskite solar cell. The quantity of hysteresis has significantly decreased by adjusting precursor ratios and thickness of devices layers. The main factor of hysteresis in perovskite solar cells is built-in field screening resulting from ion migration and minority carriers' recombination. In the proposed structures, the reduction of minority carriers decreases recombination in the forward scan. The thickness of the absorber layer of a primary (single-layer) solar cell is 450 nm as the same as the proposed structures in which aggregate thickness is 450 nm. In the single-layer absorber structure, the least quantity of the hysteresis was obtained by 0.0508 with the most precursor quantity. The optimization of thickness and precursor ratio demonstrated the reduction of hysteresis by ∼64% in two-layer absorber structures and ∼88.3% in three-layer absorber structures compared to the single-layer structure.

Comparative Study on the Direct Current Electrical Conduction in Monolayer and Bilayer Plasma Polymerized Thin Films

A comparative study on the nature of direct current electrical conduction in the monolayer and bilayer plasma polymerized thin films has been discussed in this article. The plasma polymerized pyrrole (PPPy) monolayer, plasma polymerized N,N,3,5-tetramethylaniline (PPTMA) monolayer and plasma polymerized pyrrole-N,N,3,5-tetramethylaniline (PPPy-PPTMA) bilayer thin films were deposited at room temperature onto glass substrates by using a parallel plate capacitively coupled glow discharge reactor. The current density-voltage (J-V) characteristics and the conductivity-voltage (σ-V) characteristics have been studied to analyze the direct current conduction mechanism in PPPy, PPTMA monolayer and PPPy-PPTMA bilayer thin films. The observed results have been presented in this paper. The J-V and σ-V characteristics of PPPy and PPTMA monolayer thin films of different thicknesses indicated an increase in electrical conduction and also an increase in conductivity in the films of lower thicknesses. It is also observed that PPTMA thin films are more conductive than that of PPPy thin films. As a result the PPPy-PPTMA bilayer thin films of different thicknesses and different deposition time ratios indicated an increase in conductivity as the proportion of PPTMA is increased in the films. In addition to that, from the J-V and σ-V characteristics of PPPy, PPTMA and PPPy-PPTMA thin films of same thickness, it is observed that the current conduction and the conductivity in the bilayer thin films is less compared to the monolayer thin films. This unusual result has been explained by studying ideal and real bilayer thin films. It is also seen that in the low voltage region, the current conduction obeys Ohm’s law while the charge transport phenomenon appears to be the space charge limited conduction (SCLC) in the higher voltage regions.

Characterization of Luminescent Down-Shifting Spectral Conversion Effects on Silicon Solar Cells with Various Combinations of Eu-Doped Phosphors.

Luminescent down-shifting (LDS) spectral conversion is a feasible approach to enhancing the short-wavelength response of single junction solar cells. This paper presents the optical and electrical characteristics of LDS spectral conversion layers containing a single species or two species of Eu-doped phosphors applied to the front surface of silicon solar cells via spin-on coating. The chemical composition, surface morphology, and fluorescence emission of the LDS layers were respectively characterized using energy-dispersive X-ray analysis, optical imaging, and photoluminescence measurements. We also examined the LDS effects of various phosphors on silicon solar cells in terms of optical reflectance and external quantum efficiency. Finally, we examined the LDS effects of the phosphors on photovoltaic performance by measuring photovoltaic current density–voltage characteristics using an air-mass 1.5 global solar simulator. Compared to the control cell, the application of a single phosphor enhanced efficiency by 17.39% (from 11.14% to 13.07%), whereas the application of two different phosphors enhanced efficiency by 31.63% (from 11.14% to 14.66%).

Modelling and experimental validation of polarization behavior of airbreathing microfluidic fuel cell using some common fuels: Methanol, ethanol and sodium borohydride

• MFC was fabricated with the prepared anode and airbreathing cathode. • A mathematical model is developed by considering various losses at anode and cathode. • The performance of the cell was assessed by evaluating polarization characteristics. • The predictions of the model-equations are validated to the experimental observations. Airbreathing microfluidic fuel cell (MFC) is emerging as the potential energy source for prospective use in glucose sensors, pacemakers, healthcare diagnostics, mobile phones, and DNA analysis devices, etc. A mathematical model of airbreathing MFC can aid in the explanation of a system as well as the prediction of behavior. In this line of work, the mathematical model for an airbreathing MFC was developed. Moreover, various losses such as activation, ohmic, and concentration overpotentials at anode and cathode were taking into account in the development of mathematical model. This developed model was validated with experimental data on current density vs. cell voltage characteristics at different fuel concentrations of 0.25 M to 1 M (CH 3 OH, C 2 H 5 OH) and 0.05 M to 0.3 M (NaBH 4 ) along with cell temperatures (33 °C, 50 °C and 65 °C). For these experiments, the electrocatalysts used to prepare the anodes were Platinum-Ruthenium (Pt-Ru) (30%:15% by wt.)/high surface area carbon (C HSA ) (fuel: CH 3 OH, C 2 H 5 OH), and Platinum (40% by wt.)/C HSA (fuel: NaBH 4 ). The cathodes were prepared using Pt (40% by wt.)/C HSA . The model's findings are in agreement with the experimental results well. Model prediction equation fairly reflected the influence of process variables such as fuel/electrolyte concentration and cell temperature on the prediction. The standard deviation values are found very low (0.02 to 0.082), indicating that developed mathematical model can be utilized in development of devices for industrial along with lab based applications. A high standard deviation, on the other hand, implies that the values are spread out across a higher range.

New conjugated polymer/fullerene nanocomposite for energy storage and organic solar cell devices: Studies of the impedance spectroscopy and dielectric properties

A new conjugated polymer poly(1,4-phenylene−ethynylene)-alt-poly(1,4-phenylene-vinylene) s (PPE−PPVs) abbreviated P18-8_18-8 is blended with fullerene (PCBM) to fabricate an organic solar cell with a structure ITO/PEDOT:PSS/P18-8_18-8/PCBM/LiF/Al. Current density-voltage (J-V) characteristics, complex impedance (Z* =Z′-jZ′′), dielectric loss (ε′′), dielectric loss tangent (tan(δ)), and complex electric modulus (M*= M′+jM′′) were investigated in dark and under illumination. As the frequency increase, the ε′′was decreased for all applied voltages in dark due to the deformation and relaxation polarization contributions. The lower M′ values found at low frequency region were attributed to the long-range mobility of charge carriers. Furthermore, the variation of M′′ with angular frequency obtains its maximum value at all applied voltages, causing a peak at a certain frequency. Frequency-dependent conductance (σ) displays a power-law dependence “s” which increased with applied voltage, and it is higher than unity. At bias voltage equal to 0 V and under illumination, the capacity at the interface between the polymer and the fullerene is electrically more homogeneous. The conductivity increased because the trapped charges acquire the necessary energy to escape from the interface and the hopping time found was reduced.

Fabrication of (ZnO)x: (Cu)1-x/PSi Solar Cell Using Laser Induced Plasma Technique

Fabrication of PSi is generated successfully depending upon photo-electrochemical etching process. The purpose is to differentiate the characterization of the PSi monolayer based on c-silicon solar cell compared to the bulk silicon alone. The surface of ordinary p-n solar cell has been reconstructed on the n-type region of (100) orientation with resistivity (3.2.cm) in hydrofluoric (HF) acid at a concentration of 2 ml was used to in order to enhance the conversion efficiency with 10-minute etching time and current density of 50 mA/cm2, The morphological properties (AFM) as well as the electrical properties have been investigated (J-V). The atomic force microscopy investigation reveals a rugged silicon surface with porous structure nucleating during the etching process (etching time), resulting in an expansion in depth and an average diameter of (40.1 nm). As a result, the surface roughness increases. The electrical properties of prepared PS, namely current density-voltage characteristics in the dark, reveal that porous silicon has a sponge-like structure and that the pore diameter increases with increasing etching current density and the number of shots increasing this led that the solar cell efficiency was in the range of (1-2%), resulting in improved solar cell performance.

RuO2 Nanorods as an Electrocatalyst for Proton Exchange Membrane Water Electrolysis.

A custom-built PEM electrolyzer cell was assembled using 6” stainless-steel ConFlat flanges which were fitted with a RuO2 nanorod-decorated, mixed metal oxide (MMO) ribbon mesh anode catalyst. The current density–voltage characteristics were measured for the RuO2 nanorod electrocatalyst while under constant water feed operation. The electrocatalytic behavior was investigated by making a series of physical modifications to the anode catalyst material. These experiments showed an improved activity due to the RuO2 nanorod electrocatalyst, resulting in a corresponding decrease in the electrochemical overpotential. These overpotentials were identified by collecting experimental data from various electrolyzer cell configurations, resulting in an improved understanding of the enhanced catalytic behavior. The micro-to-nano surface structure of the anode electrocatalyst layer is a critical factor determining the overall operation of the PEM electrolyzer. The improvement was determined to be due to the lowering of the potential barrier to electron escape in an electric field generated in the vicinity of a nanorod.

Performance and stability improvement in organic photovoltaics using non-toxic PEIE interfacial layers

The improvement in current density–voltage characteristics and external quantum efficiency of organic photovoltaics with non-toxic polyethylenimine ethoxylated (PEIE) as a modified layer between the electron transport layer and the active layer were demonstrated. The mechanisms of carrier transport, photon generation current, and the carrier recombination influenced by the PEIE layer were systematically studied. An extra PEIE layer was demonstrated having a shorter relaxation time via pump-probe spectroscopy, which provides better charge transfer ability. From capacitance-voltage measurement, the effective capacitance of the device increase with an addition PEIE layer, corresponding to the increase of accumulation carriers generated at the interfaces. Furthermore, electrochemical impedance spectroscopy elucidated that the PEIE layer can reduce the carrier recombination probability in the devices. As a result, the lifetime of the devices with a PEIE layer is improved as compared to the devices without PEIE layer. • A non-toxic PEIE layer was demonstrated as having a shorter carrier relaxation time via pump-probe spectroscopy, which provides better charge transfer ability in OPV. •The non-toxic PEIE layer not only provides larger effective capacitance of the device resulting from amount of accumulation carriers generated at the interfaces, but also reduces the carrier recombination probability. •The stability of the devices with a PEIE layer is also improved as the device performance can keep within 90 % compared to its original PCE values after 1400-h measurement in a nitrogen-filled glove box without encapsulation.

Photodetector based on silicon-graphene heterojunction fabricated through rubbing-in technology

This article provides an insight into the fundamental physics of a rubbed-in graphene over silicon (Si) Schottky photodiode for its affordable applications in visible light and infrared (IR) irradiation. The graphene powder was deposited over the surface of boron-doped Si (p-Si) through rubbing-in (rolling-pressing) technology. The maximum reversed biased current observed was −75 microampere at −5 V and the rectifying ratio of 240 was obtained experimentally at 1 V. The current density-voltage characteristics of the p-Si-graphene junction were investigated, then samples were measured for its rectifying ratio and results showed the tendency of a photodiode detector to operate under IR and visible light regions. The device was saturated at the open-circuit voltage values of 15 mV for infrared and 1.8 mV for visible light, respectively. The surface morphology of the device was performed through scanning electron and atomic force microscopy. The reason behind the device performance has been studied considering its junction quality, low shunt resistance, bulk, and surface recombination mechanism which drastically may affect device performance. Hence, further layers and device optimization techniques were proposed to enhance photodiode performance. The study allows us to follow footsteps toward the fabrication of fast responsive, large-scale, and budget-friendly photodiode by using transfer-less and budget-free fabrication technology for proposing efficient photo-detectors on large scale as well as for educational purposes.

IImproved performance of CdS powder-based hybrid solar cells through surface modification

The effects of surface modification of CdS through organic Eosin-Y, indoline D205, and Ru-based complex N719 and N3 dyes on CdS-based hybrid solar cells were studied. Chemical bath deposition (CBD) and doctor blade methods were in turn employed to fabricate the CdS specimens on Indium-Tin Oxide (ITO) covered glass substrates. P3HT material with and without dye coatings was covered through a spin-coater on the surface of CdS specimens. Ag paste was then deposited on the surface of P3HT to obtain hybrid solar cells. Structural analysis indicated that CdS powders showed a cubic growth with the preferred orientation of (111). Morphological analysis demonstrated that CdS powders exhibited hierarchical morphology and the morphology turned to granular structure with some porosity upon deposition of both N3 dye and P3HT layers. Absorption plots indicated that Eosin-Y dye loading led to a rise in the absorbance values of CdS specimens. After dye loading, photoluminescence data of CdS-based heterostructure illustrated a decrement in the luminescence intensity, implying that effective exciton dissociation was obtained. Current density-voltage (J-V) characteristics of the hybrid solar cells depicted that the best overall efficiency was observed for Eosin-Y-modified cell as 0.135%. This proved that surface modification by Eosin-Y dye led to a better interfacial contact between CdS and P3HT bilayer due to the enhancement in the charge separation.

Hydrogen-assisted low-temperature plasma-enhanced chemical vapor deposition of thin film encapsulation layers for top-emission organic light-emitting diodes

In this work, we developed a single high-performance SiNx encapsulation layer that can be directly integrated into organic devices by low-temperature plasma-enhanced chemical vapor deposition (PECVD). We investigated a hydrogen-assisted low-temperature PECVD process at a temperature of 80 °C. The thin film density improved with an increased hydrogen gas ratio, and the moisture permeability was less than 5 × 10−5 g/m2·day. To verify the stability of the PECVD process, we applied the SiNx encapsulation layer directly to top-emitting organic light-emitting diodes. The results showed minor changes in the current-density–voltage characteristics after the PECVD process, as well as high reliability after a water dipping test.

Multipeak Emissions and Electrical Properties of ZnO/Si Heterojunctions Based on ZnO Nanoflakes by Spin Coating Technique

ZnO/Si heterojunctions have been fabricated by spinning ZnO nanoflakes on the p-type single crystal silicon by using the spin coating technique. Photoluminescence spectra of as-grown and annealed ZnO/Si heterojunctions have been recorded under the excitation of 336 nm. Multipeaks between ∼360 nm and ∼430 nm from annealed ZnO/Si heterojunctions have been analyzed, the origins of which have been ascribed to the effects of one or multiple LO phonons. The rectifying effects can be observed from the prototypical devices based on ZnO/Si heterojunctions. Although the parameters obtained by analyzing the current density-voltage characteristics are away from those from the ideal device, it is believed that ZnO/Si heterojunctions in the present work will be a potential candidate in the optoelectronic field through modulating and optimizing the fabrication conditions.

Enhanced properties of low-cost carbon black-graphite counter electrode in DSSC by incorporating binders

Carbon-based counter electrodes of dye-sensitized solar cells (DSSCs) such as carbon black-graphite composite (CB/Gr) have received unprecedented interest in recent years due to their ease of fabrication, good corrosion resistance, and low cost compared to platinum (Pt) electrodes. However, the poor surface adherence between the carbon counter electrodes (CE) and FTO substrate, low surface area, and poor inter-particle connection between the carbon materials have consistently become a major challenge. In order to overcome these issues, we have fabricated CB/Gr by incorporating binders of titanium (IV) isopropoxide (TTIP), and zirconium (IV) dioxide (ZrO2) as the counter electrodes for the DSSC. The performance of the CE is characterized by four-point probe conductivity measurement, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and current density voltage (J-V) characteristics. The results revealed that incorporating binders to the CB/Gr has improved the series resistance (RS) and charge transfer resistance (RCT), which enhances the short-circuit current density (JSC), fill factor (FF), and the power conversion efficiency (PCE) of the device. The TTIP binder in CB/Gr CE exhibited superior performance in DSSC is largely attributed to the formation of TiO2 in situ with small particle size of about 100 nm, leading to enhanced intimate contact between the carbon materials, high surface area, and better surface adherence between counter electrode and the FTO substrate. Our findings, thereby, offer the possibility to engineer and optimize the energy levels of CE in an effort to develop a high-performing DSSC counter electrode.

Microwave-Assisted Synthesis of Bi2S3 and Sb2S3 Nanoparticles and Their Photoelectrochemical Properties.

Bi2S3 and Sb2S3 nanoparticles were prepared by microwave irradiation of single-source precursor complexes in the presence of ethylene glycol as a coordinating solvent. The as-synthesized nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray (EDX), photoluminescence (PL), and UV–vis near-infrared (NIR) spectroscopy. Their electrochemical potential was examined in [Fe(CN)]4–/[Fe(CN)]3– by cyclic and square wave voltammetry (CV and SWV) and electrochemical impedance spectroscopy (EIS). GCEBi2S3 and GCESb2S3 exhibit promising electrochemical performance and a higher specific capacitance of about 700–800 F/g in [Fe(CN)]4–/[Fe(CN)]3. Thin films of Bi2S3 and Sb2S3 were successfully incorporated in the fabrication of solar cell devices. The fabricated device using Bi2S3 (under 100 mW/cm2) showed a power conversion efficiency (PCE) of 0.39%, with a Voc of 0.96 V, a Jsc of 0.00228 mA/cm2, and an FF of 44%. In addition, the device exhibits nonlinear current density–voltage characteristics, indicating that Bi2S3 was experiencing a Schottky contact. The Sb2S3-based solar cell device showed no connection in the dark and under illumination. Therefore, no efficiency was recorded for the device using Sb2S3, which indicated the ohmic nature of the film. This might be due to the current leakage caused by poor coverage. The nanoparticles were found to induce similar responses to the conventional semiconductor nanomaterials in relation to photoelectrochemistry. The present study indicates that Bi2S3 and Sb2S3 nanoparticles are promising semiconductor materials for developing optoelectronic and electrochemical devices as the films experience Schottky and Ohmic contacts.

Preparation and Characterization of Thin-Film Solar Cells with Ag/C60/MAPbI3/CZTSe/Mo/FTO Multilayered Structures.

New solar cells with Ag/C60/MAPbI3/Cu2ZnSnSe4 (CZTSe)/Mo/FTO multilayered structures on glass substrates have been prepared and investigated in this study. The electron-transport layer, active photovoltaic layer, and hole-transport layer were made of C60, CH3NH3PbI3 (MAPbI3) perovskite, and CZTSe, respectively. The CZTSe hole-transport layers were deposited by magnetic sputtering, with the various thermal annealing temperatures at 300 °C, 400 °C, and 500 °C, and the film thickness was also varied at 50~300 nm The active photovoltaic MAPbI3 films were prepared using a two-step spin-coating method on the CZTSe hole-transport layers. It has been revealed that the crystalline structure and domain size of the MAPbI3 perovskite films could be substantially improved. Finally, n-type C60 was vacuum-evaporated to be the electronic transport layer. The 50 nm C60 thin film, in conjunction with 100 nm Ag electrode layer, provided adequate electron current transport in the multilayered structures. The solar cell current density–voltage characteristics were evaluated and compared with the thin-film microstructures. The photo-electronic power-conversion efficiency could be improved to 14.2% when the annealing temperature was 500 °C and the film thickness was 200 nm. The thin-film solar cell characteristics of open-circuit voltage, short-circuit current density, fill factor, series-resistance, and Pmax were found to be 1.07 V, 19.69 mA/cm2, 67.39%, 18.5 Ω and 1.42 mW, respectively.