Near-infrared to visible light optical upconversion by direct tandem integration of organic light-emitting diode and inorganic photodetector

The authors report a hybrid organic/inorganic optical upconversion device that converts 1.5 mu m infrared light to similar to 520 nm visible light. The device was made by direct tandem integration of an inorganic InGaAs/InP photodetector with an organic light-emitting diode (OLED). Optical upconversion with an external efficiency of 0.7% W/W at room temperature has been achieved. Interfacial structure at the inorganic-organic interface was found to play a vital role in enabling the integration of the hybrid tandem upconverter. Both sulfur-terminated InP surface and nanocarbon fullerene interlayer were found crucial to form a good interface contact, permitting continuous flow of photocarriers from the inorganic detector into the OLED. (c) 2007 American Institute of Physics.