Electroluminescence (EL) devices, using 4, 4′,4′′-tris (2-methylphenyl- phenylamino) triphenylamine (m-MTDATA) as hole-transporting material and bathocuproine (BCP) as an electron-transporting material, were fabricated, which emitted bright green light peaked at 520nm instead of the emission of m-MTDATA or BCP. It was attributed to the exciplex formation and emission at the interface of m-MTDATA and BCP. EL performance was significantly enhanced by a thin mixed layer (5nm) of m-MTDATA and BCP inserted between the two organic layers of the original m-MTDATA/BCP bilayer device. The trilayer device showed maximum luminance of 1,205cd/m 2 at 8V. At a luminance of 100cd/m 2 , the power efficiency is 1.64cd/A. Commission International De L’Eclairoge (CIE) color coordinates of the output spectrum of the devices at 8V are x=0.244 and y=0.464. These devices also showed photovoltaic (PV) properties, which were sensitive to UV light. The PV diode exhibits high open-circuit voltage (V oc ) of 2.10V under illumination of 365nm UV light with 2mW/cm 2 . And the short-circuit current (I sc ) of 92.5×10 −6 A/cm 2 , fill factor (FF) of 0.30 and power conversion efficiency (η e ) of 2.91% are respectively achieved. It is considered that strong exciplex emission in an EL device is a good indicator of efficient charge transfer at the organic interface, which is a basic requirement for good PV performance. Both the bilayer and trilayer devices showed EL and PV properties, suggesting their potential use as multifunction devices.