Tsuneyasu Shota, Watanabe Rikuya, Takeda Naoki, Uetani Kojiro, Izakura Shogo, Kasuya Keitaro, Takahashi Kosuke, Satoh Toshifumi
Department of Media Engineering, Graduate School of Engineering, Tokyo Polytechnic University, 1583 Iiyama, Atsugi, Kanagawa 243-0297, Japan.
The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan.
Nanomaterials (Basel). 2021 Mar 10;11(3):697. doi: 10.3390/nano11030697.
Powder electroluminescent (EL) devices with an electric field type excitation are surface light sources that are expected to have a wide range of practical applications, owing to their high environmental resistance; however, their low luminance has hindered their use. A clarification of the relationship between the properties of the film substrates and the electroluminescence is important to drastically improve light extraction efficiency. In this study, powder EL devices with different substrates of various levels of surface roughness and different optical transmittances were fabricated to quantitatively evaluate the relationships between the substrate properties and the device characteristics. A decrease in the surface roughness of the substrate caused a clear increase in both the current density and the luminance. The luminance was found to have a direct relationship with the optical transmittance of the substrates. The powder EL device, which was based on a cellulose nanofiber film and was the smoothest and most transparent substrate investigated, showed the highest luminance (641 cd/cm) when 300 V was applied at 1 kHz.
具有电场型激发的粉末电致发光（EL）器件是表面光源，由于其高环境耐受性，有望具有广泛的实际应用；然而，其低亮度阻碍了它们的使用。阐明薄膜基板的特性与电致发光之间的关系对于大幅提高光提取效率很重要。在本研究中，制造了具有不同表面粗糙度水平和不同光学透射率的不同基板的粉末EL器件，以定量评估基板特性与器件特性之间的关系。基板表面粗糙度的降低导致电流密度和亮度均明显增加。发现亮度与基板的光学透射率有直接关系。基于纤维素纳米纤维膜且是所研究的最光滑和最透明的基板的粉末EL器件，在1 kHz下施加300 V时显示出最高亮度（641 cd/cm²）。
