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Enhancement of open circuit voltage of CdTe solar cell
摘要： In the present work, FTO/CdS/CdTe/Te/Al superstrate structured solar cell has been fabricated using thermal evaporation method. A 40 nm thin layer of P-type tellurium has been incorporated between CdTe and back contact to reduce the potential energy barrier by improving the quality of interfaces. The fabricated device characterized using UV–Visible-NIR spectroscopy and I–V measurement. The tellurium interlayer plays a vital role in enhancing the performance of the device. The fabricated device generated open circuit voltage (Voc) of 0.7 V.
关键词： Open-circuit voltage (Voc),I–V characteristics,Thermal evaporator,Solar cell,Cadmium Telluride (CdTe),UV–Visible-NIR spectroscopy
更新于2025-09-19 17:13:59
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Inert gas cluster formation in sputter-deposited thin film CdTe solar cells
摘要： Magnetron sputtering is widely used for thin film deposition because it is a relatively low temperature process which also produces films with excellent uniformity. Unfortunately, in its use for the deposition of thin film CdTe devices, the inert working gas from the magnetron can incorporate into the film during the growth process and aggregate into large subsurface clusters during postprocessing. The gas clusters often occur at the CdS/CdTe interface causing delamination and blisters up to about 30 μm in diameter are readily observable on the film’s surface. The surface blisters are observed after postprocessing with CdCl2 at an elevated temperature but smaller inert gas clusters of several nanometres in diameter can be observed using high resolution transmission electron microscopy before the CdCl2 treatment. In this paper, these effects are investigated both experimentally and using molecular dynamics modelling. Some suggestions are also made as to how the effect might be minimised and higher efficiency solar devices fabricated.
关键词： Solar Cells,Cadmium Telluride,Argon bubbles,Molecular Dynamics,High Resolution Electron Microscopy,Magnetron Sputtering
更新于2025-09-19 17:13:59
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Influence of ZnTe separation layer thickness on optical properties in CdTe/ZnTe double quantum dots on Si substrates
摘要： We investigate the influence of the ZnTe separation layer thickness on the photoluminescence (PL) dynamics of CdTe/ZnTe double quantum dots (DQDs) on Si substrates. The results clarify that the DQD's structure effectively improves the limit of the carrier collection and the thermal stability of the corresponding single-layer QDs. The unusual temperature-dependent PL is explained using the single model for thermal redistribution of carrier states. This model indicates that the main nonradiative process at high temperatures is caused by scattering via multiphonons with longitudinal optical phonon energy of about 19–21.3 meV. The confinement-induced mixing and electron-carrier coupling effects cause blue-shift and enhanced PL intensity. We propose that the separation layer controls carrier dynamics in optoelectronic devices by modulating the thermal escape and e-h pairs in the intermixing layers.
关键词： Quantum dots,Silicon substrate,Cadmium telluride,Thermal escape,Carrier confinement
更新于2025-09-16 10:30:52
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Wet chemical etching of cadmium telluride photovoltaics for enhanced open-circuit voltage, fill factor, and power conversion efficiency
摘要： Cadmium telluride (CdTe) is one of the leading photovoltaic technologies with a market share of around 5%. However, there still exist challenges to fabricate a rear contact for ef?cient transport of photogenerated holes. Here, etching effects of various iodine compounds including elemental iodine (I2), ammonium iodide (NH4I), mixture of elemental iodine and NH4I (I?/I3? etching), and formamidinium iodide were investigated. The treated CdTe surfaces were investigated using Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The CdTe devices were completed with or without treatments and tested under simulated AM1.5G solar spectrum to ?nd photoconversion ef?ciency (PCE). Based on Raman spectra, XRD patterns, and surface morphology, it was shown that treatment with iodine compounds produced Te-rich surface on CdTe ?lms, and temperature-dependent current–voltage characteristics showed reduced back barrier heights, which are essential for the formation of ohmic contact and reduce contact resistance. Based on current–voltage characteristics, the treatment enhanced open-circuit voltage (VOC) up to 841 mV, ?ll factor (FF) up to 78.2%, and PCE up to 14.0% compared with standard untreated CdTe devices (VOC ; 814 mV, FF ; 74%, and PCE ; 12.7%) with copper/gold back contact.
关键词： open-circuit voltage,fill factor,Cadmium telluride,wet chemical etching,photovoltaics,power conversion efficiency
更新于2025-09-12 10:27:22
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Performance Analysis of 0.4–1.2-μm CdTe Solar Cells
摘要： Thin-?lm cadmium telluride (CdTe) solar cells with an absorber thickness range of 0.4–1.2 μm were fabricated by close-space sublimation on a transparent MgZnO window layer. Microscopy cross sections showed that a signi?cant fraction of the CdTe crystallites extended throughout the absorber layer, and capacitance measurements demonstrated that the absorbers were depleted into forward bias. Current and ?ll factor loss analyses were used to identify dominant loss mechanisms in the devices as a function of absorber thickness, and photoluminescence measurements were increasingly in?uenced by back-surface recombination as the absorber was made thinner. The thinner CdTe devices showed modest current and ?ll-factor reduction but overall good diode quality, and the highest ef?ciency of 15% was achieved with 1.2-μm CdTe.
关键词： Close-space sublimation (CSS),photoluminescence (PL),loss analysis,thin cadmium telluride (CdTe)
更新于2025-09-12 10:27:22
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Influences of buffer material and fabrication atmosphere on the electrical properties of CdTe solar cells
摘要： The electrical properties such as interface energy barriers, defect energy levels, and densities dictate the performance of thin film solar cells. Here, we show that these properties can be quantified in cadmium telluride (CdTe) thin‐film solar cells using admittance spectroscopy‐based techniques. Our results reveal that the electrical properties in CdTe thin‐film solar cells depend on both buffer material and the fabrication atmosphere. We find that only a negligible front contact barrier exists at the CdS/CdTe front junction regardless of the fabrication atmospheres, while an obvious front barriers are observed at the ZnMgO (ZMO)/CdTe junctions. Both CdS/CdTe and ZMO/CdTe solar cells exhibit back contact barrier. The energy level of defects is shallower in CdS/CdTe cells than in ZMO/CdTe cells. The fabrication atmosphere influences the electrical properties, i.e., an oxygen‐free atmosphere reduces the front and back barrier heights and lowers the energy level of defects. The results provide critical insights for understanding and optimizing the performance of CdTe thin‐film solar cells.
关键词： admittance spectroscopy,interface barriers,cadmium telluride,equivalent circuit,photovoltaic cells
更新于2025-09-11 14:15:04
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Degradation of Mg-doped zinc oxide buffer layers in thin film CdTe solar cells
摘要： Cadmium Sulphide is the conventional n-type bu?er layer used in thin ?lm Cadmium Telluride solar cells. It is well known that Cadmium Sulphide causes optical losses and sulphur di?uses into the absorber during high temperature activation. Sputter-deposited Mg-doped ZnO (MZO) has been shown to be an attractive bu?er layer for Cadmium Telluride solar cells due to its transparency and tuneable band gap. It is also stable to high temperature processing and avoids di?usion of elements into the cadmium telluride absorber during the cadmium chloride activation treatment. However, degradation is observed in solar cells incorporating MZO bu?er layers. Analysis of the MZO ?lm surface potential has revealed signi?cant ?uctuations in the thin ?lm work function once the layer is exposed to the atmosphere following deposition. These ?uctuations are attributed to the high reactivity to water vapour of the MgO contained in the MZO ?lms. This has been analysed using X-ray Photoelectron Spectroscopy to determine corresponding changes in the surface chemistry. The Zinc Oxide component is relatively stable, but the analysis shows that MgO forms a Mg(OH)2 layer on the MZO surface which forms a secondary barrier at the MZO/CdTe interface and/or at the interface between MZO and the Fluorine-doped SnO2. This a?ects the Fill Factor and as a consequence it degrades the conversion e?ciency.
关键词： Surface contamination,Degradation,Thin ?lm solar cells,Cadmium telluride,Magnesium-doped zinc oxide,Hydroxide,Bu?er
更新于2025-09-11 14:15:04
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Cadmium telluride quantum dots/graphene oxide/poly vinyl acetate (CdTe QDs/GO/PVAc) nanocomposite: a novel sensor for real time gamma radiation detection
摘要： The design of organic/inorganic nanoparticles hybrids provides the great potential for the fabrication of γ-ray sensor systems. Herein, structural and dosimetric properties of the gamma irradiated poly vinyl acetate (PVAc) doped with cadmium telluride quantum dots (CdTe QDs) and graphene oxide (GO) nanoflakes have been investigated. Thioglycolic acid (TGA) capped water-soluble CdTe QDs and (GO) nanoflakes are synthesized and characterized. Then, CdTe QDs/GO/PVAc sensors were formed by post-depositing CdTe and GO over polymer matrix. The photophysical interactions between nanoparticles and organic polymer have been investigated using ohmic contact detectors with two gold coated electrodes. Real time dose rate information of the sensors such as sensitivity, repeatability, and the linearity of dose rate response were assessed. A wider photoelectric response range and wider gamma harvesting range were observed in the resultant hybrid gamma sensor at a standard bias voltage with respect to non-hybrid CdTe QDs/PVAc sensors.
关键词： dosimetry,graphene oxide,poly vinyl acetate,radiation detection,Cadmium telluride quantum dots
更新于2025-09-11 14:15:04
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Temperature-Dependent Photoluminescence in CdTe/ZnTe Triple Quantum Dots
摘要： We studied the optical properties of CdTe/ZnTe quantum dots (QDs) in single, double, and triple QD structures by measuring the temperature-dependent photoluminescence (PL). On going from the single to the triple QD structures, the PL peak position of the QDs was blue shifted. This blue-shift was attributed to compressive strain imparted by the separation layers and to material intermixing. Temperature-dependent PL measurements of the triple QD structures showed that, as the temperature increased, the PL peak intensity for the 4.5-monolayer (ML) QDs decreased less than it did for the 3.0- and the 3.5-ML QDs. The activation energy of the 4.5-ML QDs in the triple QD structures was larger than that of the corresponding 4.5-ML QDs in the single QD structures. The reason for this is that, as the temperature increases, some carriers disappear due to non-radiative recombination, but many carriers in the 3.0- and the 3.5-ML QDs move to the 4.5-ML QDs in the triple QD structures, and those carriers then undergo radiative recombination.
关键词： Cadmium telluride,Photoluminescence,Triple quantum dots,Activation energy
更新于2025-09-11 14:15:04
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Synthesis and characterization of Polymer/Silica/QDs fluorescent nanocomposites with potential application as printing toner
摘要： In this work cadmium telluride quantum dots (CdTeQDs) were prepared via one-pot synthesis microwave assisted. Afterwards, CdTeQDs/silica (SiO2)/nigrosine (nigro)/poly (styrene co-methyl methacrylate) (PSCMM) fluorescent nanocomposite (CSNP) powders were prepared via ultrasonic treatment and post drying at 60 ℃. The samples were characterized by UV-vis absorbance, X-Ray diffraction (XRD) and transmission electron microscopy (TEM). Finally, successful printing tests were performed on security paper at 130 ℃. These results show the potential of this nanocomposite to be used as security toner.
关键词： Cadmium Telluride,Security Toner,Nanocomposite,Quantum Dots
更新于2025-09-10 09:29:36