화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.153, No.4, H71-H77, 2006
Design and optical properties of ZnS : Mn thin-film electroluminescent devices on 2D SiO2 corrugated photonic crystal substrates
We studied the characteristics of ZnS:Mn thin-film electroluminescence (TFEL) display devices in which the glass substrate had been modified with a two-dimensional (2D) SiO2 corrugated photonic crystal (PC) pattern. The finite-difference time-domain (FDTD) method was used to predict the behavior of 2D corrugated PC ZnS:Mn TFEL devices with varying PC structural parameters. Based on the optimal parameters derived from the FDTD calculations, a 2D SiO2 corrugated PC layer was introduced onto the glass substrate of a typical ZnS:Mn TFEL structure by two-step irradiated hologram lithography and reactive ion etching. Experiments conducted under typical operating conditions showed that incorporation of the 2D corrugated structure improved the light extraction luminance at 40 V above the threshold voltage by over 3.1-fold compared to the conventional ZnS:Mn TFEL device, without noticeable degradation of the electrical characteristics. This improvement originates from the liberation of the photons trapped in the high-index guiding layers.