Development of Ceramic Type Thin-Film Electroluminescent Devices High-Luminance Flat Panel Lamp

高亮度、高效率的大面积薄膜电致发光（TFEL）器件不仅可以作为平板显示器，还可以作为平板灯。采用医生刀法制备了大面积BaTiO_3陶瓷片。在不使用研磨或抛光工艺的情况下，获得了表面光滑、厚度为0.14 ~ 0.4mm的BaTiO_3陶瓷片。采用低压化学气相沉积（MOCVD）技术在陶瓷片上制备了ZnS: Mn薄膜发射层。为了获得具有高亮度和高发光效率的ZnS: Mn TFEL器件，优化了BaTiO_3陶瓷片作为绝缘层的介电性能和ZnS: Mn薄膜作为发射层的后电条件。采用博士刀法制备BaTiO_3绝缘陶瓷片，研制了不经研磨或抛光加工的高效ZnS: Mn TFEL器件。当驱动频率为5、1kHz和60Hz时，采用厚度约为0.4mm的陶瓷片制备的ZnS: Mn TFEL器件获得了16000、5800和750cd/m^2以上的发光效率和12.5、11和61m/W的橙色发光效率。此外，在200 V的5kHz正弦波电压驱动下，ZnS: Mn TFEL器件的发光效率为11.5lm/W，亮度为9500 cd/m^2。在使用绝缘陶瓷片的TFEL器件中获得的发光效率高于传统的双绝缘层型TFEL器件。采用Ga_2O_3: Mn或Ga_2Oa_3: Cr薄膜发射的TFEL器件获得了较高的绿色或红色发光度

Large area thin-film electroluminescent (TFEL) devices with high luminance as well as high luminous efficiency have been developed not only as Flat panel displays but also as flat panel lamps. The large area BaTiO_3 ceramic sheet was formed using a doctor blade method. Smooth surface BaTiO_3 ceramic sheets with a thickness of 0.14-0.4mm were obtained without the use of grinding or polishing processes. The ZnS : Mn thin-film emitting layr was deposited onto the ceramic sheets by a low-pressure chemical vapor deposition (MOCVD) technique. To obtain ZnS : Mn TFEL devices which exhibit a high luminance as well as high-luminous efficiency, both the dielectric properties of BaTiO_3 ceramic sheet as the insulating layr and postannealing conditions of ZnS : Mn thin film as the emitting layr were optimized.High-liminous efficiency ZnS : Mn TFEL devices using a BaTiO_3 insulating ceramic sheet prepared by the doctor blade method without the use of grinding or polishing processes were developed. Luminances above 16000,5800 and 750cd/m^2 and maximum luminous efficiencies of 12.5,11 and 61m/W for orange emission were obtained in a ZnS : Mn TFEL device using a ceramic sheet with a thickness of about 0.4mm, when driven at 5,1kHz and 60Hz, respectively. In addition, a luminous efficiency of 11.5lm/W and a luminance of 9500 cd/m^2 were obtained in a ZnS : Mn TFEL device driven by a 5kHz sinusoidal wave voltage of 200 V.The luminous efficiencies obtained in TFEL devices using an insulating ceramic sheet were higher than those reported in conventional double-insulating-layr-type TFEL devices. High luminances for green or red emisssion were obtained in TFEL devices with a Ga_2O_3 : Mn or a Ga_2Oa_3 : Cr thin-film emitting