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%).

Research on a Partial Aperture Factor Measurement Method for the Agri Onboard Calibration Assembly

A partial aperture onboard calibration method can solve the onboard calibration problems of some large aperture remote sensors, which is of great significance for the development trend of increasingly large apertures in optical remote sensors. In this paper, the solar diffuser reflectance degradation monitor (SDRDM) in the onboard calibration assembly (CA) of the FengYun-4 (FY-4) advanced geostationary radiance imager (AGRI) is used as the reference radiometer for measuring the partial aperture factor (PAF) for the AGRI onboard calibration. First, the linear response count variation relationship between the two is established under the same radiance source input. Then, according to the known bidirectional reflection distribution function (BRDF) of the solar diffuser (SD) in the CA, the relative reflectance ratio coefficient between the AGRI observation direction and the SDRDM observation direction is calculated. On this basis, the response count value of the AGRI and the SDRDM is used to realize the high-precision measurement of the PAF of the AGRI B1 ~ B3 bands by simulating the AGRI onboard calibration measurement under the illumination of a solar simulator in the laboratory. According to the determination process of the relevant parameters of the PAF, the measurement uncertainty of the PAF is analyzed; this uncertainty is better than 2.04% and provides an important reference for the evaluation of the onboard absolute radiometric calibration uncertainty after launch.

Enhanced Perovskite Solar Cell Performance by Adding Magnesium Acetate Using Two-Step Spin-Coating Method

The poor stability of perovskite materials is a problem of concern in commercialization. In this study, we investigated the doping of magnesium cations (Mg2+) in PbI2 to improve the stability and efficiency of perovskite solar cells. The doping effect of Mg2+ can increase the crystallization rate. The perovskite film fabricated structure consists of ITO/TiO2/perovskite/CuO. The fabrication method used is a two-stage spin coating. The concentrations of MgAc2 were used 0, 0.75, 1, and 1.25 mg ml−1. The characterizations used are XRD (X-Ray Diffraction), UV-Vis, SEM-EDX. While the performance of solar cells is measured using a solar simulator. The XRD pattern shows that the sample has a crystal structure of MAPbI3, PbI2, and CuO phases. The MAPbI3 lattice parameter increased with increasing Mg acetate concentration. The grain size of the perovskite layer is between 5 - 15 μm, with a thickness of about 30 μm. The efficiency of perovskite solar cells increases with the increasing concentration of MgAc2.

Photovoltaic Characteristics of GaSe/MoSe2 Heterojunction Devices

The two-dimensional materials have the thickness of an atomic layer level and are expected as alternative materials for future electronics and optoelectronics due to their specific properties. Especially recently, transition metal monochalcogenides and dichalcogenides have attracted attention. Since these materials have a band gap unlike graphene and exhibit a semiconductor property even in a single layer, application to a new flexible optoelectronics is expected. In this study, the photovoltaic characteristics of a GaSe/MoSe2 heterojunction device using two-dimensional semiconductors, p-type GaSe and n-type MoSe2, were investigated. The heterojunction device was prepared by transferring GaSe and MoSe2 onto the substrate which the titanium electrodes were fabricated through a mechanical peeling method. The current–voltage characteristics of the GaSe/MoSe2 heterojunction device were measured in a dark condition and under light irradiation using a solar simulator. The irradiation light intensity was changed from 0.5 to 1.5 sun. It was found that when the illuminance was increased in this illuminance range, both the short-circuit current and the open-circuit voltage increased. The open-circuit voltage and the energy conversion efficiency were 0.41 V and 0.46% under 1.5 sun condition, respectively.

Improved efficiency in dye sensitized solar cell (DSSC) by nano-MIL-101(Cr) impregnated photoanode

In the present work, MIL-101 nanoparticles (nano-MIL-101(Cr)) metal–organic framework (MOF) structure was synthesized by hydrothermal method, and characterized via Fourier transform infrared, X-ray diffraction, and scanning electron microscopy techniques. The optoelectronic application of MOFs was investigated for the first time. For this purpose, the dye-sensitized solar cells (DSSCs) consisting of the synthesized nano-MIL-101(Cr) impregnated photoanode (PA) was fabricated, and photovoltaic, photoelectric properties of them were investigated under different illumination intensities, and the obtained results were compared with reference one. The DSSC fabricated by impregnated PA showed better photovoltaic properties than reference one. It is obtained the power conversion efficiency (PCE) of about 0.828 and fill factor (ff) of 0.656 for the fabricated DSSC based on nano-MIL-101(Cr) impregnated PA under illumination power of 100 mW/cm2 by AM1.5 G solar simulator. For the reference DSSC, PCE, and ff is about 0.468 and 0.28, respectively. The PCE of the fabricated device based on nano-MIL-101(Cr) is ∼77% greater than the reference one. The improvement in the efficiency is because of good electrocatalytic activity, large pores, and high surface area of nano-MIL-101(Cr). The nano-MIL-101(Cr) can be used in organo-optoelectronic device fabrication to obtain better performance.

Silicon Particles/Black Paint Coating for Performance Enhancement of Solar Absorbers

The availability of fresh drinkable water and water security is becoming a global challenge for sustainable development. In this regard, solar stills, due to their ease in operation, installation, and utilization of direct sunlight (as thermal energy), promise a better and sustainable future technology for water security in urban and remote areas. The major issue is its low distillate productivity, which limits its widespread commercialization. In this study, the effect of silicon (Si) particles is examined to improve the absorber surface temperature of the solar still absorber plate, which is the major component for increased distillate yield. Various weight percentages of Si particles were introduced in paint and coated on the aluminum absorber surface. Extensive indoor (using a self-made halogen light-based solar simulator) and outdoor testing were conducted to optimize the concentration. The coatings with 15 wt % Si in the paint exhibited the highest increase in temperature, namely, 98.5 °C under indoor controlled conditions at 1000 W/m2 irradiation, which is 65.81% higher than a bare aluminum plate and 37.09% higher compared to a black paint-coated aluminum plate. On the other hand, coatings with 10 wt % Si reached up to 73.2 °C under uncontrolled outdoor conditions compared to 68.8 °C for the black paint-coated aluminum plate. A further increase in concentration did not improve the surface temperature, which was due to an excessive increase in thermal conductivity and high convective heat losses.

Used For Space Irradiation Environment Simulation Equipment Property Analysis of Metal Mirror

With the development of space science and technology, the requirements of spacecraft environment simulation tests are gradually increasing, and radiation environment simulation has also attracted much attention. Based on space radiation environment simulation equipment of vertical metal reflector material in the solar simulator performance analysis, the systematic analysis of the influence factors of metal reflector, aimed at straight metal mirror blank material performance analysis, including the mechanics analysis and optical analysis, the performance to the blank material for testing. The test results show that the aluminum alloy 6061T6 billet used in the metal mirror can meet the requirements of high irradiation vertical solar simulator, and lay a solid foundation for the subsequent solar irradiation simulation, space illumination simulation and spacecraft thermal environment simulation.