Wide-Band High Concentration-Ratio Volume-Holographic Grating for Solar Concentration

Abstract

Efficient and low-cost solar-energy collection has become the focus of many research works. This paper proposes a recording method and an experimental verification of a wide-band, large-angle, and high concentration-ratio volume-holographic grating for solar concentration. We applied the Kogelnik coupled-wave theory and photopolymer diffusion model to analyse the formation mechanism and influencing factors on the diffraction efficiency of monochromatic volume-holographic gratings. We design and construct a three-color laser-interference system to record three monochromatic volume-holographic gratings. The best recording conditions are determined by experiment and simulation. A trichromatic volume-holographic grating is obtained by gluing the three monochromatic gratings together. The experimental results show that the trichromatic volume-holographic grating with a working angle of 6.7° and a working band of visible light has a light concentration ratio of 149.2 under an illumination of the combined recorded three-color beams, and that under sunlight is 27.2. We find that the proposed trichromatic volume-holographic grating for light concentration offers the advantages of wide band and high light concentration ratio, which provide a reference for solar concentration.

Building-Integrated Concentrating Photovoltaics based on a low-toxicity photopolymer

“…In this case, the photopolymer is also based in acrylamide, a toxic material. In 2020, Wang et al [26] achieved an HSC consisting of 3 HLs stuck as a multilayer, using Bayfol HX200 material. Notice that each of the HLs was recorded at different wavelengths, namely, 473, 532, and 639 nm, respectively.…”

“…On the one hand, acceptance angles of up to around 35 • HSC have been developed using angular multiplexing holographic optical elements [25] and hybrid PV systems for direct and diffuse light [11]. On the other hand, high diffraction efficiency HSCs have been obtained using different designs [11,21,26]. Vorndran et al produced a spectrum-splitting PV module in 2016 that used an array of two off-axis volume holographic lenses (20 µm thick and 2 cm focal length), which achieved 85% diffraction efficiency and 38 • acceptance angle, but based on dichromated gelatin [11].…”

Design and fabrication of volume holographic optical couplers for a range of non-normal incidence angles

“…These VHOEs can be fabricated in lightweight polymer films via lightinduced refractive index modulation of the photosensitive layers which occurs due to polymerization and diffusion of monomers within the layer (31), (32). Key parameters that affect the final diffraction efficiency of VHOEs are the layer thickness, the exposure intensity and energy used, the ratio between the energies of the object and reference beams, the dark reaction time (time between recording and curing) and the spatial frequency (32), (33), (34).…”

Development of high efficiency and wide acceptance angle holographic solar concentrators for breakthrough photovoltaic applications

“…9, 10 So far different research groups have developed different holographic solar concentrators. [11][12][13][14][15] The maximum acceptance angle obtained with double layer or multiplexed lenses range between 30 • to 50 • , 11,13,15 while the maximum diffraction efficiencies have been obtained with multilayer devices or with a small number of multiplexed holographic lenses (HLs). 12,14 In this work we will present, to the best of our knowledge, the best low-toxicity multiplexed holographic solar concentrator obtained so far.…”

“…[11][12][13][14][15] The maximum acceptance angle obtained with double layer or multiplexed lenses range between 30 • to 50 • , 11,13,15 while the maximum diffraction efficiencies have been obtained with multilayer devices or with a small number of multiplexed holographic lenses (HLs). 12,14 In this work we will present, to the best of our knowledge, the best low-toxicity multiplexed holographic solar concentrator obtained so far. First, four peristrophic multiplexed holographic solar concentrators will be recorded by rotating the sample in each new holographic configuration 7.4 • , each of them is based on seven HLs recorded and superimposed on different spots of the same plate.…”