High-efficiency single-layer organic light-emitting diode based on green fluorescent protein

We have fabricated a molecular organic light-emitting device comprising indium-tin oxide/a molecular organic layer/aluminum in which the organic layer is a green fluorescent protein. The device exhibits peak external quantum and power efficiencies of 8 +/- 0.2% and 13 +/- 0.7 lm W-1 at a current of J = 1.5 A m(-2), respectively. In addition, the turn-on voltage is 2.5V for 1 cd m(-2) and the maximum luminance achieved is 1275 cd m(-2). This good performance can be explained by the presence of singlet-excited states, leading to a high internal efficiency.