Color Tunable Light-Emitting Diodes Based on Polymer/Inorganic Heterojunction

By using p-type polymer poly(2,5-Didodecyloxy-1, 4-Phenylenylenevinylene) (PDDOPV) and n-type inorganic material ZnO:Zn, the electronluminescent (EL) emission from bilayer device based on polymer/inorganic hetero-junction was successfully demonstrated. In comparison with single layer polymer device, with dc voltage of 10V, the brightness and luminous efficiency of bilayer device were enhanced 14 and 26 times, respectively. The EL spectrum of bilayer device is not identical to the characteristic emission spectrum of either PDDOPV or ZnO:Zn, and shifts continuously towards to short wavelength direction as the applied voltage increases.