Enhancement of photoluminescence of glass phosphor by nanoimprint of moth-eye structure

Abstract

We demonstrated that a moth-eye surface pattern on the luminous inorganic glass could enhance the photoluminescence (PL) intensity notably. A moth-eye pattern of a square array of cones at pitch of 250 nm was fabricated on Eu3+-doped MgF2MgOBaOB2O3 glass by thermal nanoimprinting at 520°C. A simulation with rigorous coupled-wave analysis demonstrated that the surface structure could reduce the surface reflectance in the optical input for the excitation wavelength of 405 nm, i.e., 11.1% for p-polarized light, 10.6% for s-polarized light, and 4.1% for non-polarized light in total of a half round angle for the irradiation from a surface light source. The angularly dependent PL of the excitation angle on the nanoimprinted glass was measured by an excitation of UV laser diode ( = 405 nm). The enhancements of 30% for p-polarized light and 39% for s-polarized light were observed at the incident angle = 5°.