- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Influence of the energy dependence of the absorption coefficient on the solar energy conversion efficiency
摘要： In most cases, when the ef?ciencies of a single or multi-gap (with intermediate bands) solar cell are evaluated, the energy dependence of the absorption coef?cients is ignored. In this work we will evaluate the range of optical thickness and average absorption coef?cients in which this dependence should be considered. For this study we use different absorption coef?cients generated randomly as a function of the energy. In many practical cases, the ef?ciencies are lower than those expected.
关键词： optical thickness,energy dependence,intermediate-band solar cells,solar energy conversion efficiency,absorption coefficient
更新于2025-09-23 15:21:21
-
Role of ion energy flux on the structural and morphological properties of silicon oxy-nitride composite films deposited by plasma focus device
摘要： Crystalline silicon oxy-nitride (SiON) composite films are deposited on Si substrate for multiple (5, 15, 25 and 50) focus shots (FS) by plasma focus device. The X-rays diffraction patterns reveal the development of various diffraction peaks related to Si, Si3N4, and SiO2 phases which confirms the formation of SiON composite film. The intensity of Si3N4 (1 0 2) plane is linearly increased with the increase of FS. The Si3N4 (1 0 2) phase does not nucleate for 5 FS. Raman analysis confirms the formation of β–Si–N phase. Raman and Fourier transform infrared spectroscopy analysis reveals that the strength of chemical bonds like Si–N, Si–O formed during the deposition process of SiON composite films is associated with the bonds intensity which in turn depends on the number of FS. The field emission scanning electron microscopic analysis reveals that the surface morphology like size, shape and distribution of micro/nano-dimensional particles, film compactness and the formation of micro-rods, micro-teethes and micro-tubes of SiON composite films is entirely associated with the rise in substrate surface transient temperature which in turn depends on the increasing number of FS. The EDX spectrum confirms the presence of Si (22.5 ± 4.7 at. %), N (13.4 ± 4.5 at. %) and O (54.7 ± 11.3 at. %) in the SiON composite film. The thickness of SiON composite film deposited for 50 FS is found to ～ 15.47 μm.
关键词： composite,crystallite size,micro-tubes,Plasma focus,thickness,XRD
更新于2025-09-23 15:21:21
-
Relationship between the Lamina Cribrosa, Outer Retina, and Choroidal Thickness as Assessed Using Spectral Domain Optical Coherence Tomography
摘要： To evaluate the characteristics and relationship between peripapillary choroidal thickness (pCT), lamina cribrosa thickness (LCT), and peripapillary outer retinal layer thickness (pORT) as determined using spectral domain optical coherence tomography (SD-OCT) enhanced depth imaging (EDI).
关键词： Outer retinal thickness,Lamina cribrosa thickness,Optical coherence tomography,Choroidal thickness,Glaucoma
更新于2025-09-23 15:21:01
-
Normal Value Ranges for Central Retinal Thickness Asymmetry in Healthy Caucasian Adults Measured by SPECTRALIS SD-OCT Posterior Pole Asymmetry Analysis
摘要： PURPOSE. To determine the normal variation in central retinal thickness asymmetry in healthy Caucasian adults using the posterior pole asymmetry analysis (PPAA) of a SPECTRALIS spectral-domain optical coherence tomography (SD-OCT) device. METHODS. Healthy Caucasian individuals aged between 18 and 45 years with a visual acuity of minimum 20/20 and a spherical equivalent between (cid:2)1.5 and t1.5 diopters were recruited. Retinal thickness and retinal nerve ?ber layer thickness (RNFL) were using measured SPECTRALIS SD-OCT. Inter- and intraocular differences in central retinal thickness were calculated using the PPAA. The association between age, sex, and interocular asymmetry was evaluated by a linear model with Gaussian correlation structure. RESULTS. A total of 105 individuals, 30 men and 75 women, were studied. The mean age 6 SD was 28.8 6 7.87 years. The grand mean interocular retinal thickness asymmetry was 5.6 lm (95% con?dence interval [CI]: 4.6–6.5) and the grand mean intraocular retinal thickness asymmetry was 8.3 lm (95% CI: 6.8–9.9) in the right eye and 8.4 lm (95% CI: 6.7–10.0) in the left eye. The highest local asymmetries were found in the nasal corners of macula were the posterior pole thickness map overlaps the temporal vascular arches. A slight general age and sex effect on the mean interocular retinal thickness asymmetry was found to be respectively 0.04 lm/year (95% CI: 0.02–0.06 lm) and 0.54 lm (95% CI: 0.19–0.88 lm) for men compared with women. CONCLUSIONS. Statistically signi?cant physiological asymmetries in inter- and intraocular central retinal thickness exist. This must be considered when early signs of glaucoma or other pathologies are evaluated based on the retinal thickness asymmetry.
关键词： glaucoma posterior segment,normal value ranges for retinal thickness asymmetry,posterior pole retinal thickness asymmetry analysis
更新于2025-09-23 15:21:01
-
Designing Large Area Single Crystal Perovskite Solar Cells
摘要： Organic-inorganic halide single-crystal perovskite solar cells (PSCs) are promising for higher efficiency and better stability, while their development lags far behind polycrystalline counterpart. In particular, low efficiency (<5%) of large-area devices makes it challenging to be an alternative perovskite photovoltaic technology. In this perspective, we highlight the optimization of crystal growth and reduction of crystal thickness are keys to improve performance of the large-area single-crystal PSCs. After analyzing the characteristics of perovskite crystal growth methods and efficiency evolution of single-crystal PSCs, we conclude the low efficiency of large-area devices is due to conflict between low crystal quality and large crystal thickness. Then, we propose methods to grow high-quality perovskite single crystals and possible strategy to reduce the crystal thickness. Finally, investigation of key factors and exploration of large-area application are suggested to be conducted in parallel for future development of single-crystal PSCs.
关键词： large area,perovskite solar cells,single crystal,thickness reduction,crystal growth
更新于2025-09-23 15:21:01
-
Effect of film thickness and evaporation rate on co-evaporated SnSe thin films for photovoltaic applications
摘要： SnSe thin films were deposited by a co-evaporation method with different film thicknesses and evaporation rates. A device with a structure of soda-lime glass/Mo/SnSe/CdS/i-ZnO/ITO/Ni/Al was fabricated. Device efficiency was improved from 0.18% to 1.02% by a film thickness of 1.3 mm and evaporation rate of 2.5 ? s?1 via augmentation of short-circuit current density and open-circuit voltage. Properties (electrical, optical, structural) and scanning electron microscopy measurements were compared for samples. A SnSe thin-film solar cell prepared with a film thickness of 1.3 mm and evaporation rate of 2.5 ? s?1 had the highest electron mobility, better crystalline properties, and larger grain size compared with the other solar cells prepared. These data can be used to guide growth of high-quality SnSe thin films, and contribute to development of efficient SnSe thin-film solar cells using an evaporation-based method.
关键词： SnSe thin films,film thickness,co-evaporation,photovoltaic applications,evaporation rate
更新于2025-09-23 15:21:01
-
A Method of Human Eye Parameter Measurement Based on Laser Self-Mixing Interference
摘要： The eye is the most important sensory organ of the human body, and the cornea and anterior chamber are very important components In surgeries like vision correction, it is necessary to know the accurate corneal thickness and anterior chamber depth of human eyes. Their accurate measurement cannot only provide a reference for doctors, but also provide a strong guarantee of surgical results. In order to achieve high-precision measurements of human corneal thickness and anterior chamber depth, we develop an equivalent human-eye optical system and a measurement method for the thickness. This method designs an equivalent double-membrane system to simplify the physiological structure of the cornea and anterior chamber of the human eye and irradiate the double-membrane system through laser. The re?ected light returns to the laser cavity and the original light self-mixing interference, and a photodetector collects and processes the interference signals to obtain the corneal thickness and anterior chamber depth. The correctness of the theoretical calculations is veri?ed by the experimental system, and the measurement accuracy can reach the micrometer level.
关键词： self-mixing interference,anterior chamber depth,corneal thickness,confirmatory experiment,double-membrane system
更新于2025-09-23 15:21:01
-
Interfacial strain and shell thickness effect on core squeeze/stretch in core/shell quantum dots
摘要： Large surface to volume ratio in zero dimension core/shell quantum dots makes lattice mismatch induced interfacial strain vital in determining structural and optical properties of nanostructures. In this study, changes in lattice mismatch induced strain from different compressive shell (CdS–ZnS) with different thicknesses (thin and thick) are evaluated and its effect on capped core diameter is theoretically calculated. Capped core squeeze amount is compared with its initial (bare) diameter obtained from transmission electron microscopy. The capped core diameter is first calculated theoretically using effective mass approximation. Then, same diameter is obtained from modified version of effective mass approximation method that considers interfacial strain amount. Comparison of the results with bare core size obtained from transmission electron microscopy revealed effect of shell thickness imposed on capped core diameter. Results show, larger lattice mismatch between core and shell induces higher strain amount on the core thereby larger squeezes the core. At the meantime, it is shown that, thicker compressive shell enforces lower stress on core as it widens its distance from core due to lattice relaxation. Hence, core is squeezes less under thicker shell.
关键词： Capped core size,Shell thickness,Interfacial strain
更新于2025-09-23 15:21:01
-
Fabrication and luminous properties of phosphor ceramic for application in automotive laser headlight
摘要： We report on the optimization of fabrication of a ceramic phosphor plate (CPP) using α-Al2O3 as functional materials for an automotive laser headlamp. The prepared CPP shows the high luminous characteristics with increasing α-Al2O3 contents because of the light scattering of the hexagonal structure of α-Al2O3 materials. We investigated the correlation between α-Al2O3 and thickness of CPP. The luminous properties of the CPP are improved and optimized according to the variables of one. We found that the prepared sample is a potential material for future solid-state laser lighting in application as an automotive headlamp.
关键词： α-Al2O3,Luminous properties,Thickness,Laser diode,Ceramic phosphor plate
更新于2025-09-23 15:21:01
-
[Communications in Computer and Information Science] Advances in Computing and Data Sciences Volume 905 (Second International Conference, ICACDS 2018, Dehradun, India, April 20-21, 2018, Revised Selected Papers, Part I) || Assessing the Performance of CMOS Amplifiers Using High-k Dielectric with Metal Gate on High Mobility Substrate
摘要： With the increase in demand for high-performance ICs for both memory and logic applications, scaling has been continued down to 14 nm node. To meet the performance requirements, high-k dielectrics such as HfO2, ZrO2 have replaced SiO2 in the conventional MOS structure for sub-45 nm node. Correspondingly, the polysilicon gate electrode has been replaced by metal gate electrode in order to enable integration with high-k. Furthermore, the standard silicon substrate has been replaced by high mobility substrate in order to obtain desired transistor performance. While the fabrication technology for CMOS has advanced rapidly the traditional design tools used for designing circuits continues to use conventional MOS structure and their properties. This paper aims to analyze frequency response of CMOS common source ampli?er(CSA) and di?erential ampli?er by simulating in MATLAB using metal gate/high-k/Ge structure and to compare with traditionally used ampli?er design using standard MOS structure.
关键词： CMOS - Complementary Metal Oxide Semiconductor,EOT - E?ective Oxide Thickness,CSA - Common Source Ampli?er,UGB - Unity Gain Bandwidth,High-k dielectrics based ampli?er design
更新于2025-09-23 15:21:01