Organic-inorganic hybrid optical upconverter

We report a hybrid organic-inorganic optical up-converter that converts input 1.5-mu m infrared light to output visible light. The device was made by direct tandem integration of an inorganic InGaAs/InP photodetector with an organic light-emitting diode (OLED). Incoming 1.5-mu m light optical radiation is absorbed by the semiconductor p-i-n detector. The resultant photocurrent drives the OLED to emit visible light at similar to 520 nm in wavelength. The ratio of the photocurrent-induced versus dark-current-induced visible light emission was measured to be over 100 at a device bias of 14 V at room temperature. Devices with different configurations of the hole transport layer (HTL) were fabricated and tested. It was found that the devices with an HTL of C-60/CuPc/NPB exhibited a lowest turn-on voltage (similar to 3.8 V). The results show that the interfacial structure at the inorganic-organic interface plays a vital role in enabling the integration of the hybrid organic-inorganic devices.