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The effects of TiO 2 / Al 2 O 3 / MgF 2 triple-layer (TL) antireflection (AR) coating on reducing optical loss of GaInP/InGaAs/Ge triple-junction (TJ) solar cell have been investigated by using Essential Macleod Program software and Crosslight Apsys software, and compared to that of TiO 2 / Al 2 O 3 dual-layer (DL) AR coating. The DLAR and TLAR coatings have reduced the average optical reflectivity values of the TJ solar cells by around 18.9% and 22.2%, respectively. The conversion efficiency of TJ solar cell was increased by 21.29% and 29.44% with DLAR and TLAR coatings. External quantum efficiency values of TJ solar cells with DL and TLAR coating increased in full wavelength region due to the increase of photo generated current density caused by the reduction of surface reflectivity. Both simulation and experimental results showed that the TiO 2 / Al 2 O 3 / MgF 2 TLAR coating has better anti-reflecting properties over TiO 2 / Al 2 O 3 DLAR coating, and improved the overall performance of TJ solar cell more.

In this study, a high performance TiO 2 / Al 2 O 3 / MgF 2 multilayer anti-reflective (AR) coating, with an average reflectivity of 6.36% in spectral range of 300–1800 nm, applied on GaInP/GaAs/Ge triple-junction solar cell was designed by Essential Macleod Program (EMP) software. Based on the simulation results, TiO 2 , Al 2 O 3 , MgF 2 single layer and TiO 2 / Al 2 O 3 / MgF 2 multilayer AR coating samples were grown by Electron Beam Evaporation (EBE) system for 1 MeV electron beam irradiation experiment. The overall reflectivity of TiO 2 / Al 2 O 3 / MgF 2 multilayer AR coating is decreased with the increase of electron irradiation fluence due to the change of reflectivity of each AR layer caused by the refractive index changes. This result indicates that the TiO 2 / Al 2 O 3 / MgF 2 multilayer AR coating can improve the triple junction solar cell radiation resistance by achieving favorable permeability in the broadband solar spectrum, especially in 750–900 nm region where the main degradation spectral window for triple junction solar cell.

Reflection from the surface of solar panels is important factor to limit the efficiency of all of photovoltaic devices. Antireflective coatings (ARCs) can significantly reduce surface reflections and improve photovoltaic module efficiency. But, ARCs on solar glass, used in photovoltaic (PV) modules, usually located in terrible environments, which demands that ARCs must hinder moisture penetration, abrasion damage, and dirt accumulation. In this study, the films with highly antireflective properties that maintains a high durability and hydrophobic were prepared through a simple sol–gel method by using PTFE (Polytetrafluoroethylene) modified. The average transmittance of glass with ARCs was 97.86 % at 400–800 nm, which was an increase of 7.86 % compared to the bare glass. X-ray Diffraction (XRD), Fourier Transform Infrared spectrometer (FT-IR), field emission scanning electron microscope (FE-SEM), ellipsometer, atomic force microscope (AFM), UV–vis-NIR spectrophotometer and water contact angle analyzer were used to measure the surface composition, morphology, refractive index, surface roughness, optical and hydrophilic properties of the coatings. The results revealed that the deposition of PTFE modified SiO2 coating on the glass substrate had a significant enhance on the antireflection, abrasion-resistance and hydrophobic property.

The broadband antireflective coatings (ARCs) can effectively reduce the optical loss in the transmittance process and improve energy efficiency in solar cells. MgF2/SiO2 bilayer films were prepared on the surface of soda–lime substrates via sol–gel spin-coating combined with electron beam (e-beam) evaporation. The bottom layer was the MgF2 film obtained from e-beam evaporation, whereas the top layer was the nanoporous SiO2 film via sol–gel spin-coating method. The refractive indices of MgF2 and SiO2 layers at 550 nm are 1.38 and 1.12, respectively. The structural, morphological, and optical properties of the films were characterized. The effects of annealing temperature, Triton X-100 concentration, and spin-coating speed on the properties of the film were investigated. The transmittance spectra of the coatings were investigated, and the broadband antireflective performance of the bilayer structure was examined. A bilayer coating with optical properties close to the theoretical design results was obtained by optimizing the refractive index and the thickness of the double coatings. The solar transmittances of the soda–lime glass coated with the MgF2/SiO2 bilayer antireflective film increased by 8.89% at 400–800 nm. The multilayer antireflective film exhibits promising applications in photoelectric devices, high power laser systems, and antidazzle glasses.

In order to improve the oxidation resistance of TiAl substrate at high temperatures, NiAlHf coating was prepared by electron beam physical vapor deposition (EB-PVD) on the TiAl substrate. According to the measured mass gain curves, the effect of NiAlHf coating on the oxidation behavior of TiAl substrate was studied at 900, 950 and 1000 °C. X-ray diffraction (XRD) was employed to identify the phases of the surfaces at different states. The XRD results show that β-NiAl is formed after deposition and element Hf is found to be dissolved into it. A dense Al 2 O 3 protection film is formed on the coating surface after 950 °C oxidation. Scanning electron morphology (SEM) with energy dispersive spectrum (EDS) was employed to characterize the morphology and element distribution at the cross-section and the surface. During oxidation, elements diffusion occurs at the interface between the substrate and the coating. With increasing of oxidation duration, the thickness of the coating decreases and the diffusion zone changes rapidly. Micro-hardness was used to characterize the coating toughness. Its micro-hardness is about HV7050 MPa. The results show that NiAlHf coating can improve the substrate oxidation resistance at high temperatures.

Solar cells face the disadvantages of high cost, poor reliability and low conversion efficiency.In order to overcome many shortcomings of solar cells and optimize the performance of solar cells, coating anti-reflection film is one of the main optimization methods at present, so it is necessary to prepare anti-reflection film with excellent anti-reflection performance.In this paper, the research results of TiO2 based anti-reflection films are discussed. The contribution of TiO2 anti-reflection film to solar cell conversion efficiency is summarized. The preparation methods and processes are discussed.