Enhanced brightness and efficiency in organic electroluminescent devices using SiO2 buffer layers

Organic electroluminescent devices using SiO2 as a hole-injecting buffer have been fabricated. With the presence of the buffer, the luminance of the device reaches 1820 cd/m(2) at the current density of 20 mA/cm(2), which corresponds to an efficiency of 9.1 cd/A. The enhancements in brightness and efficiency are attributed to an improved balance of hole and electron injections due to blocking of the injected holes by the buffer layer and a more homogeneous adhesion of the hole transporting layer to the anode. (C) 1999 American Institute of Physics. [S0003-6951(99)02915-0].