Influences of submonolayer proteins on organic light-emitting diodes

The authors sandwiched protein molecules into the layered structure of organic light-emitting diodes (OLEDs). Light emission from the OLEDs was suppressed on the area with the protein submonolayers of 4-7 nm thick. They found that this suppression depended on the density of the proteins and light emission efficiency reflected molecular properties. A bovine serum albumin layer decreased both the current and light emission, keeping the efficiency almost unchanged. In the case of cytochrome C, the emission was suppressed while current increased, resulting in low efficiency. (C) 2007 American Institute of Physics.