Combinatorial fabrication and studies of bright white organic light-emitting devices based on emission from rubrene-doped 4,4′-bis(2,2′-diphenylvinyl)-1,1′-biphenyl

A highly bright and efficient fluorescent white organic light emitting devices (OLED) based on rubrene-doped 4,4′-bis(2,2′-diphenylvinyl)-1,1′-biphenyl (DPVBi) were analyzed. It was shown that their color can be tuned by varying the thickness and doping concentration of the doped layer. The blue DPVBi emission increased relative to the orange rubrene emission as the bias increased. The results show that the color variation is attributed to either emission from different zones in devices with a thin doped layer, or saturation of emission sites due to relatively light doping.