Near-infrared down-conversion in Yb3+:TiO2 for solar cell applications

Abstract

Near-infrared emitting phosphors of ytterbium doped titania are synthesized by precipitation method using titanium tetrachloride as a raw material. X-ray diffraction technique is to analyze the structure, ultraviolet–visible diffuse reflectance spectroscopy to determine the band gap energy and photoluminescence spectroscopy to characterize the luminescence properties of the synthesis material. The HRSEM and HRTEM are used to measure the morphology structure of the sample. This sample is excited by ultraviolet irradiation, exhibits an intense band emission near NIR region between ²F_5/2 and ²F_7/2 transition of Yb³⁺ ions using photoluminescence spectroscopy. The observation discusses the possible energy transfer mechanism between TiO₂ and Yb³⁺ ions. The results determine the synthesized material is adept for silicon based solar cells.