유기 EL 소자의 전기-광학적 특성

Abstract

Organic EL devices, which have the single-layer structure of ITO(indium-tin-oxide) /PPV(poly(p-phenylene vinylene))/cathode and the double-layer structure of ITO/PVK (poly(N- vinylcarbazole)) /PPV/cathode, were fabricated and their electro-optical properties were investigated. Experimental results, in single-layer structure, shown that the increment of temperature for thermal conversion of PPV film from 140℃ to 260℃ decreases the maximum luminance from 118.8 cd/㎡(20V) to 21.14 cd/㎡(28V) and shift the maximum peak of EL spectrum from 500nm to 580nm. The lower the work function of cathode is, the more the luminance and injection current of device. In double-layer structure, as the concentration of PVK solution decreases from 0.5 wt% to 0.05 wt%, the luminance of device increases from 70.71 cd/㎡(32V) to 152.7 ed/㎡(26V).