A metal-free, full-color stacked organic light-emitting device

We report the demonstration of a transparent, completely metal-free, full-c olor stacked organic light-emitting device (SOLED). The SOLED emits light f rom both top and bottom (substrate) surfaces with total external quantum ef ficiencies of 0.65%, 1.3%, and 2.2% for the green, blue, and red stacked su bpixels, respectively. The respective top emission quantum efficiencies for the three subpixels are 0.23%, 0.63%, and 1.6%. The angular dependence of emission colors due to microcavity effects is weak when viewed from the top device surface. This metal-free SOLED is from 21% to 50% transparent over the entire visible spectral range. Capability for top emission makes this d evice suitable for integration with electronic components in active matrix display backplanes. (C) 1999 American Institute of Physics. [S0003-6951(99) 01302-9].