The principle architecture of a bottom emission OLED incorporating the intrinsic emission layers into the Novaled PIN OLED® technology by using doped transport layers: holes are injected from the anode and transported by p-hole transport layer (p-HTL) to the emitting layer (EML). Electrons are injected from the cathode and transported by the n-electron transport layer (n-ETL). Recombination of the charge carriers takes place in the EML and light is emitted