Optical properties of neodymium-containing polymethylmethacrylate films for the organic light emitting diode color filter

In order to improve the primary color purity of the organic light emitting diode (OLED), neodymium(Nd)-containing polymethylmethacrylate (PMMA) films have been fabricated by a solvent casting method, and their optical properties have been investigated as functions of Nd content in films. The study has revealed that absorption in Nd-containing PMMA films is due to intratransition within the 4f shell of the Nd3+ ion, and that it becomes larger with an increase in the Nd concentration in films. In OLED devices with color filters, luminance from unnecessary emissive light is sufficiently reduced, resulting in a wider color gamut and higher color purity.