유전재료와 후면전극에 따른 저전력 소비형 AC Powder EL 소자 제조 및 광전기적 특성 |
이강렬, 박성 |
명지대학교 무기재료공학과 |
Preparation and Optoelectric Characteristics of Low Power Consumption Type AC Powder EL Devices with Dielectrics and Rear Contact |
Kang-Ryeol Lee, Sung Park |
Department of Inorganic Materials Engineering, Myongji University |
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ABSTRACT |
AC powder EL devices were fabricated by screen printing method with the dielectric materials in insulating layer and the electrical resistivity of rear electrode. Brightness and current density were measured at voltage range of 50∼300 $V_{rms}$ to estimate optoelectrical properties of AC powder EL devices, respectively. Frequency generator was used as system producing frequency and voltage of a sine wave. Brightness and current density were measured by luminometer and multimeter. Also, dielectric constant for dielectric layer was measured by impedance analyser after preparing thick film. Dielectric constant was improved with amount of $TiO_2$ to $BaTiO_3$ powder. By applying such a process to dielectric layer of low cost AC powder EL device, brightness was improved to 50 cd/$m^2$ at similar current density. Dielectric constant $BaTiO_3$ powder by solution combustion process is better than commercial $BaTiO_3$ powder. By applying to that of low power consumption AC powder EL device, brightness was improved to 85 cd/$m^2$. Brightness of AC powder EL device was relatively decreased by control of electrical resistivity of rear electrode, current density was also decreased. |
Key words:
AC powder EL devices, Screen printing method, Dielectric layer, Contact, Brightness and current density, Optoelectrical properties |
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