Volume 39, Issue 1, 2018
Monday, November 13, 2017
Electron transport in light emitting semiconducting polymers is often limited by traps. By studying the role of Caesium carbonate (Cs2CO3), Caesium Nitride (CsN3), Caesium Fluoride (CsF) are chosen as the electron injection layer, it is discovered that CsF has the ability to reduce the electron traps followed by CsN3 and then Cs2CO3 with trap density of 1.5 x 1018 cm-3 , 2.22 x 1018 cm-3 , 3.03 x 1018 cm-3 , respectively. We also found out that for such materials, charge balance as often obtained from comparison between electron and hole only devices, is not a good predictor for current efficiency. In fact, highest efficiency is obtained using Cs2CO3 with 11.9 lm/W for superyellow poly-(p-phenylenevinylene) at 1000 cdm-2.