Spectral photoluminescence properties of YAG: Ce, R (R: Gd3+, Pr3+, Gd3+ and Pr3+) transparent fluorescent thin film prepared by pulse laser deposition

In order to overcome the shortcomings of insufficient red light component and poor thermal stability of commercial white light emitting diode (WLED), YAG:Ce, R (R: Gd 3+ , Pr 3+ , Gd 3+ and Pr 3+ ) fluorescent thin films were prepared by pulse laser deposition (PLD). The composition and microstructure, photoluminescence properties, and red-enhanced mechanism of co-doped YAG fluorescent thin films, as well as the electroluminescence behavior of the corresponding WLEDs were investigated. Results showed that the doping of Pr 3+ caused the emission spectrum energy of Ce 3+ to migrate, and an emission peak appeared at 606 nm in the red region. The doping of Gd 3+ caused the emission spectrum of Ce 3+ to shift to the red region, and the main peak position of the Ce 3+ emission spectrum is red-shifted from 523 nm to 548 nm. The YAG:Ce,Pr,Gd fluorescent film not only realized the improvement of red light components and red-shift, but also increased the energy transmission efficiency from 33.3% to 51.9%. Moreover, results of the color coordinate analysis also showed that the co-doping of Gd 3+ and Pr 3+ made the luminescence closer to the red region, reducing the color temperatures and hues changed to warm. Thus, tri-doped transparent fluorescent thin film were prospective for WLED application.