Single-step alkaline etching of deep silicon cavities for chip-scale atomic clock technology

This paper presents the results of experiments on the development of the technology of MEMS alkali vapor cells for a miniature quantum frequency standard. The classical design of a two-chamber silicon cell containing an optical chamber, shallow filtration channels and a technical container for a solid-state alkali source was implemented in a single-step process of wet anisotropic silicon etching. To prevent the destruction of the filtration channels during etching of the through silicon cavities, the shapes of the compensating structures at the convex corners of the silicon nitride mask were calculated and the composition of the silicon etchant was experimentally found. The experiments results were used in the manufacture of chip-scale atomic clock cells containing vapors of 87Rb or 133Cs isotopes in the neon atmosphere.

Effect of Photoconductivity of Silicon Oxide Passivation Film on the Performance of Crystalline Silicon Cell and Module

In the paper, the effect of different deposition process of silicon oxide passivation film on the performance of crystalline silicon cell and module was studied. It was found that the thermal oxidation passivation film has better passivation effect than ozone oxidation passivation film at room temperature, and the cell and module has good stability and low attenuation. The thermal oxidation passivation effect is related to the film thickness. The thicker the film thickness is, the better the anti-PID (potential induced attenuation) performance is. The results can provide reference for photovoltaic industry.

Influence of Solar Concentrator in the Form of Luminescent PMMA on the Performance of a Silicon Cell

The methods of production of electricity from renewable sources are currently highly researched topics. The reason for this is growing social awareness regarding the environmental impact of traditional energy technologies. The main aim of this study is to describe the results of using silicon cell technology and dye concentrator in a single system. The experiment presented in the paper was conducted in a laboratory environment using a dye concentrator in the form of tinted and luminescent acrylic glass (polymethyl methacrylate, PMMA). The experiment was conducted using a few measurement calibrations for the described system, such as different temperatures of the researched silicon cell or different intensity of illuminance from a solar simulator. The results of the experiment showed increase in the performance of the solar cell between 0.05% and 1.42% depending on the pigments used in the concentrator. The highest results were achieved for luminescent red PMMA and on average the improvement was 1.21%. This shows us the potential for the implementation of a luminescent dye concentrator in solar electric technology.

Research on Performance Improvement of Photovoltaic Cells and Modules Based on Black Silicon

This paper mainly studied the electrical performance improvement of black silicon photovoltaic (PV) cells and modules. The electrical performance of the cells and modules matched with black silicon was optimized through three different experiments. Firstly, in the pre-cleaning step, the effect of lotion selection on the cell performance was studied. Compared with alkaline lotion, using acidic lotion on black silicon wafer can achieve an efficiency improvement of the black silicon cell by nearly 0.154%. Secondly, the influence of oxygen flux control of the thermal oxidation step on the improvement of cell efficiency was studied. The addition of the thermal oxidation step and its oxygen flux control resulted in an efficiency increase of the black silicon cell of nearly 0.11%. The most optimized volume control of the oxygen flux is at 2200 standard cubic centimeter per minute (SCCM). Finally, in the module packaging process, the selection of components will also greatly affect the performance of the black silicon PV module. The most reasonable selection of components can increase the output power of the black silicon PV module by 6.13 W. In a word, the technical indication of the electrical performance improvement suggested in this study plays an important guiding role in the actual production process.

Optimization of the Secondary Optical Element of a Hybrid Concentrator Photovoltaic Module Considering the Effective Absorption Wavelength Range

Hybrid concentrator photovoltaic (CPV) architectures that combine CPV modules with low-cost solar cells have the advantage of functioning well in modest direct normal irradiance (DNI) regions as well as high-DNI regions, where these architectures allow for higher performance in a limited space. For higher performance of a hybrid CPV module, we optimized the secondary optical element (SOE) using raytracing software and conducted experimental measurements that consider the effective wavelength range. Our experiments with the optimized SOE (θ = 30°, h = 15 mm) demonstrated a maximum output power on the triple-junction cell and polycrystalline silicon cell of 212.8 W/m2 and 5.14 W/m2, respectively.