Using Spin-Coated Silver Nanoparticles/Zinc Oxide Thin Films to Improve the Efficiency of GaInP/(In)GaAs/Ge Solar Cells

We synthesized a silver nanoparticle/zinc oxide (Ag NP/ZnO) thin film by using spin-coating technology. The treatment solution for Ag NP/ZnO thin film deposition contained zinc acetate (Zn(CH(3)COO)(2)), sodium hydroxide (NaOH), and silver nitrate (AgNO(3)) aqueous solutions. The crystalline characteristics, surface morphology, content of elements, and reflectivity of the Ag NPs/ZnO thin film at various concentrations of the AgNO(3) aqueous solution were investigated using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, atomic force microscopy, and ultraviolet–visible–near infrared spectrophotometry. The results indicated that the crystalline structure, Ag content, and reflectance of Ag NP/ZnO thin films depended on the AgNO(3) concentration. Hybrid antireflection coatings (ARCs) composed of SiN(x) and Ag NPs/ZnO thin films with various AgNO(3) concentrations were deposited on GaInP/(In)GaAs/Ge solar cells. We propose that the optimal ARC consists of SiN(x) and Ag NP/ZnO thin films prepared using a treatment solution of 0.0008 M AgNO(3), 0.007 M Zn(CH(3)COO)(2), and 1 M NaOH, followed by post-annealing at 200 °C. GaInP/(Al)GaAs/Ge solar cells with the optimal hybrid ARC and SiN(x) ARC exhibit a conversion efficiency of 34.1% and 30.2% with V(oc) = 2.39 and 2.4 V, J(sc) = 16.63 and 15.37 mA/cm(2), and fill factor = 86.1% and 78.8%.