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Cell viability assessments of green synthesized water-soluble AgInS <sub/>2</sub> /ZnS core/shell quantum dots against different cancer cell lines
摘要： Chalcopyrite quantum dots (QDs) have emerged as a safe alternative to cadmium-based QDs for bio-applications. However, the research on AgInS2 chalcopyrite QDs has not been widely explored in terms of their toxicity. Herein, we report a synthesis of biocompatible AgInS2/ZnS QDs via a greener approach. The emission intensity of the as-synthesized AgInS2 core QDs was enhanced 2-fold after the ZnS shell growth. X-ray diffraction revealed the tetragonal crystal structure of QDs, and high-resolution transmission electron microscope images show that the QDs are spherical in shape and crystalline in nature. Cell viability assays conducted on different cell lines, such as HeLa, A549, and BHK-21 cells, indicated that AgInS2/ZnS QDs are least toxic at a QD concentration range of 100 lg/mL. The ?uorescent microscope analysis of A549 cells incubated with AgInS2/ZnS QDs shows that the QDs were accumulated in the cell membranes. The as-synthesized AgInS2/ZnS QDs are less toxic and eco-friendly, and can be used for biolabeling.
关键词： cell viability,AgInS2/ZnS,biolabeling,Chalcopyrite quantum dots,biocompatibility
更新于2025-11-19 16:46:39
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Synthesis and Electrical Transport Properties of CuInGaTe2
摘要： Copper Indium Gallium di-telluride (CIGT) single crystals were synthesized by a special modified Bridgman technique for crystal growth. Our XRD patterns clearly exhibited single phase. The temperature dependence of the electrical conductivity σ(T), Hall coefficient RH(T) in CuInGaTe2 single crystals have been demonstrated over the temperature range 143-558 K for the first time. The Hall coefficient sign confirms the samples displays the p-type conducting. The temperature dependence of the conductivity, Hall coefficient, Hall mobility, and charge carriers concentration were investigated were presented with a clear and effective pictures. CuInGaTe2 single crystals revealed electrical band gaps (or "transport gaps") ranging from 0.64 eV to 0.85 eV. The results obtained from electrical conductivity and carrier concentration revealed the sample p-type with acceptor energy level equal to ≈ 0.027 eV. From the obtained experimental data, the main fundamental physical constants and others for crystals under consideration have been estimated.
关键词： Single crystals,Electrical conductivity,Cu–III–VI2 Chalcopyrite semiconductors
更新于2025-09-23 15:22:29
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Potassium Treatments for Solution-Processed Cu(In,Ga)(S,Se) <sub/>2</sub> Solar Cells
摘要： Cu(In,Ga)(S,Se)2 (CIGSe, CIGSSe) has emerged as an attractive thin-film solar cell absorber material owing to its high light absorption coefficient and tunable bandgap. In CIGSSe processing and fabrication, the use of alkali treatments has been implemented as sodium doping is considered a requirement for high efficiency CIGSSe solar cell devices and has been used extensively. One of the more significant developments in recent years has been the discovery of the beneficial effects that potassium post-deposition treatments have on vacuum-processed CIGSSe solar cells as they are responsible for a major increase in CIGSSe solar cell performance. Here, we conduct a study of the effect of potassium treatments to solution-processed CIGSSe films grown from colloidal sulfide-based nanoparticle inks. By adding potassium through e-beam evaporation of KF prior to selenization and grain growth, we find that the grain growth of CIGSSe is enhanced with potassium addition and that a larger-grained film results compared to untreated selenized CIGSSe film, similar to what is observed in sodium-treated films. We also observe through XPS that films treated with K show the presence of the high-bandgap K-In-Se surface phase. Fabricating devices, we find that films that have been subjected simultaneously to both sodium and potassium treatments have enhanced optoelectronic performance mainly manifested in higher open-circuit voltage and higher short-circuit current.
关键词： CIGS,alkali treatment,Cu(In,Ga)(S,Se)2,solution-processed solar cells,potassium fluoride,chalcopyrite solar cell,sodium fluoride
更新于2025-09-23 15:21:01
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Lithium-Doping Effects in Cu(In,Ga)Se2 Thin-Film and Photovoltaic Properties
摘要： The beneficial effects of heavy alkali-metals such as K, Rb, and Cs in enhancing Cu(In,Ga)Se2 (CIGS) photovoltaic efficiencies are widely known, though the detailed mechanism is still open for discussion. In the present work, the effects of the lightest alkali-metal, Li, on CIGS thin-film and device properties are focused upon and compared to the effects of heavy alkali-metals. To date, the beneficial effects of elemental Li on Cu2ZnSnS4 (CZTS) photovoltaic devices in enhancing efficiencies have been reported in the literature. On the other hand, it is shown in the present work that the beneficial effects of Li on CIGS are not so significant. In contrast to the effects of Na or Rb in enhancing CIGS (112) growth orientation, Li was revealed not to affect CIGS growth orientation. The most distinctive feature observed between Li and other alkali-metals was the elemental depth profile in CIGS films. Namely, Na and heavier alkali-metals show a concentration peak near the surface region (relatively Cu-poor region) of CIGS films, whereas elemental Li showed no such trend, suggesting that Li has no significant effect on CIGS surface modification. Nonetheless, Li was found to have some effect in enhancing the PL peak intensity and photovoltaic performance of CIGS, though the effect is relatively small in comparison to that obtained with other alkali-metals.
关键词： CIGS,lithium,thin-film solar cell,rubidium,chalcogenide,chalcopyrite,alkali-metal
更新于2025-09-23 15:21:01
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Optical characteristics of overstressed nanosecond discharge in atmospheric pressure air between chalcopyrite electrodes
摘要： The results of the investigation of the optical characteristics of a high-current nanosecond discharge in atmospheric pressure air between chalcopyrite electrodes (CuInSe2 and CuSbSe2 compounds) in conditions of overstressed discharge gap are presented. When using electrodes with a relatively large radius of curvature of the working part (3 mm) and a special system for isolating a part of the surface of the electrodes, a relatively uniform nanosecond discharge was obtained in millimeter intervals. Electrical and optical (spectral and temporal) discharge characteristics were investigated. Based on the solution of the Boltzmann equation for the electron energy distribution function, the parameters of the air plasma with small additions of the vapor of easily ionized impurity, in the form of copper vapor, were simulated.
关键词： optical characteristics,chalcopyrite electrodes,overstressed nanosecond discharge,air plasma
更新于2025-09-23 15:21:01
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Surface passivation of a Cu(In,Ga)Se2 photovoltaic absorber using a thin indium sulfide layer
摘要： The present study demonstrates the surface passivation of Cu(In,Ga)Se2 (CIGS) photovoltaic absorbers using a thin In2S3 layer and its effect on the performance of the CIGS device. Two types of CIGS samples with different surface roughness values prepared by conventional selenization of metal precursors (2-step) and three-stage co-evaporation (3-stage) were used to determine the influence of In2S3 surface passivation on CIGS surface roughness to minimize recombination at the interface of the CIGS and buffer layers. Three types of buffer layers, i.e., In2S3, CdS single layers, and an In2S3/CdS double layer, were prepared by chemical bath deposition on bare and Mo-coated substrates as well as glass/Mo/CIGS samples. The phase formation and properties of the as-prepared buffer layers were analyzed by XRD, Raman, and UV–Vis–NIR techniques. The power conversion efficiency of the CIGS solar cells was enhanced significantly for the 2-step-processed CIGS (from 6.97% to 9.89%) and slightly for the 3-stage-processed CIGS (from 10.1% to 11.0%) when passivated with In2S3. Further, both the In2S3 surface passivated 2-step- and 3-stage-processed CIGS devices exhibited high quantum efficiencies in the wavelength range of 400–550 nm. Therefore, surface passivation with In2S3 could improve the performance of CIGS devices.
关键词： Chalcopyrite,Surface passivation,Indium sulfide,Hybrid buffer,Cu(In,Ga)Se2,Double buffer
更新于2025-09-19 17:13:59
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Cu(In,Al)Se <sub/>2</sub> Photovoltaic Thin Film Solar Cell from Electrodeposited Stacked Metallic Layers
摘要： An improved technique for synthesis of Cu(In,Al)Se2 is demonstrated, associated with sequential electrodeposition of a stacked layer in the order of Cu/Al/In followed by annealing in selenium vapor. Many advantages such as adjustable constitutes composition, good polycrystalline structure, pure chalcopyrite phase, uniform and compact surface morphology are obtained compared to the film fabricated by conventional electrodeposition process. The film thickness and the concentration of each metal deposited were controlled by the flexibility parameters of deposition time. The influence of Al content on the crystal structure, surface morphology, photoelectrochemical performance, optical and electronic properties of the films were investigated. The crystal size decrease and the energy bandgap of Cu(In,Al)Se2 thin film increase gradually with the increasing Al were revealed. Impedance potential test reveals the manufactured Cu(In,Al)Se2 thin films are all p-type semiconductor and the carrier concentration increases with the Cu/(Al + In) and Al/(In + Al) ratio. Photoelectrochemical investigation of Cu(In,Al)Se2 films verified that a higher photocurrent was obtained with a relative lower Al content due to a narrower bandgap leading to lower-energy photon absorption and a lower carrier density and a larger grain size both benefiting the transfer of photogenerated carriers and decrease the recombination of charge carriers. The obtained optimum Cu(In,Al)Se2 thin film based solar cell has been theoretical modeling and simulated. A high PCE of 17.08% was gained implying its potential application in photovoltaic devices.
关键词： electrodeposition,photovoltaic,Cu(In,Al)Se2,chalcopyrite,thin film solar cell
更新于2025-09-19 17:13:59
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Application of Al-Doped (Zn, Mg)O on pure-sulfide Cu(In, Ga)S2 solar cells for enhancement of open-circuit voltage
摘要： In this study, interfacial recombination observed by activation energy (Ea) is reduced with an improvement in the built-in potential (Vbi) by raising the conduction band minimum (EC) in Al-doped (Zn, Mg)O (AZMO) layer for pure-sul?de Cu(In, Ga)S2 (CIGS) solar cells. It is observed that the optical band gap in AZMO ?lms can be widened from 3.56 to 3.97 eV with increasing Mg/(Mg + Zn) ratio from 0 to 0.23, suggesting the shift of EC toward the vacuum level. AZMO layers with Mg/(Mg + Zn) ratio of 0–0.23 are applied as transparent conductive oxide (TCO) for the pure-sul?de CIGS solar cells. The open-circuit voltage is clearly enhanced from 0.641 to 0.713 V with increasing Mg/(Mg + Zn) ratio from 0 to 0.09 and then decreased to 0.651 V at Mg/(Mg + Zn) ratio of 0.23 in the AZMO layer. Reverse saturation current density (J0) was minimized to 9.4 × 10?7 A/cm2 at Mg/(Mg + Zn) of 0.09, although J0 was 4.7 × 10?6 A/cm2 in Al-doped ZnO (Mg/(Mg + Zn) of 0). From Mott-Schottky plot, it is observed that Vbi for the pure-sul?de CIGS solar cells gradually enhanced with an increase in Mg/(Mg + Zn) from 0 to 0.23 in the AZMO layer. These results suggest that Vbi improves by controlling EC in the TCO layer, which ultimately reduces the recombination at the hetero interface owing to strengthened electric ?eld.
关键词： Al-doped (Zn, Mg)O,Chalcopyrite,Thin-?lm solar cell,Built-in potential,Conduction band minimum,Cu(In, Ga)S2
更新于2025-09-16 10:30:52
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Highlights in Applied Mineralogy || 4. Microstructure analysis of chalcopyrite-type Cu2ZnSe4 and kesterite-type Cu2ZnSnSe4 absorber layers in thin film solar cells
摘要： Thin film solar cells equipped with polycrystalline compound semiconductors as functional layer for light absorption have continuously been improved in terms of solar energy conversion efficiency, such that they became a competitive alternative to well-established silicon-based solar cells. In 1905, Einstein published a comprehensive, physical description of the photoelectric effect [1] and thus provided the theoretical framework for upcoming research of photovoltaic technologies. The emergence of photovoltaic devices, however, only started about 50 years later, and for several decades, it persisted a niche technology mainly for aerospace applications. Among others, silicon (Si) was known to belong to the group of (extrinsic) elemental semiconductors, and due to its abundance, it was the very first absorber material to be used in solar cells. Triggered by the oil crisis in the 1970s, the research of solar energy conversion technologies finally got a tremendous stimulus. As a result, research not only of silicon-based solar cells but also of other absorber layer materials based on compound semiconductors have been much more extensively endeavored. The latter were also brought into focus in order to address some severe drawbacks of silicon-based solar cells. First of all, the high energy consumption in fabricating single crystal silicon results in a quite long energy amortization time. In addition, the requirements on crystallinity and purity are extremely high while a considerable amount of material is wasted upon slicing silicon wafers. Also, during the growth of silicon single crystals a certain concentration of dopants has to be incorporated in order to induce either extrinsic p-type or n-type conductivity. Despite the energy of the band gap of silicon fitting quite well with the optimal energy determined by the solar spectrum, silicon is an indirect semiconductor whose photonic electron transition from the valence band to the conduction band needs to be assisted by a phononic momentum transfer. This requirement of coincidence between a photon of appropriate energy being absorbed and a phonon transferring impulse to the electron leads to a reduced probability of events of photoelectric charge carrier generation. Correspondingly, the absorber thickness must be augmented in order to compensate the low absorption coefficient. These aforementioned issues, eventually, gave rise to reconsider photovoltaic technologies, being both economical and ecological reasonably applicable in a more widely spread manner. These demands have paved the way for thin film solar cell technologies using compound semiconductors. Those compound semiconductors are intrinsically conductive, and they possess a higher absorption coefficient due to direct electron band transitions (Fig. 4.1).
关键词： kesterite-type,chalcopyrite-type,absorber layer materials,light absorption,microstructure analysis,photovoltaic technologies,solar energy conversion efficiency,compound semiconductors,thin film solar cells,silicon-based solar cells
更新于2025-09-16 10:30:52
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Heavy Alkali Treatment of Cu(In,Ga)Se <sub/>2</sub> Solar Cells: Surface versus Bulk Effects
摘要： Chalcopyrite solar cells achieve efficiencies above 23%. The latest improvements are due to post-deposition treatments (PDT) with heavy alkalis. This study provides a comprehensive description of the effect of PDT on the chemical and electronic structure of surface and bulk of Cu(In,Ga)Se2. Chemical changes at the surface appear similar, independent of absorber or alkali. However, the effect on the surface electronic structure differs with absorber or type of treatment, although the improvement of the solar cell efficiency is the same. Thus, changes at the surface cannot be the only effect of the PDT treatment. The main effect of PDT with heavy alkalis concerns bulk recombination. The reduction in bulk recombination goes along with a reduced density of electronic tail states. Improvements in open-circuit voltage appear together with reduced band bending at grain boundaries. Heavy alkalis accumulate at grain boundaries and are not detected in the grains. This behavior is understood by the energetics of the formation of single-phase Cu-alkali compounds. Thus, the efficiency improvement with heavy alkali PDT can be attributed to reduced band bending at grain boundaries, which reduces tail states and nonradiative recombination and is caused by accumulation of heavy alkalis at grain boundaries.
关键词： grain boundaries,alkali treatment,recombination,bulk,surface,chalcopyrite solar cells
更新于2025-09-16 10:30:52