Demonstration and Evaluation of p‐Type and n‐Type ZnO Nanoparticles‐Based Homojunction UV Light‐Emitting Diodes

Abstract

The world's first homojunction UV light‐emitting diode (LED) based on both p‐type and n‐type ZnO nanoparticles (NPs) is demonstrated. Nitrogen‐doped ZnO and gallium‐doped ZnO NPs are provided to fabricate p‐type and n‐type NP layers, respectively. The LEDs with the structures of p‐ZnO/GZO and p‐ZnO/n‐ZnO/GZO are fabricated. These devices show near UV electroluminescence (EL) at room temperature and emission power doubled by inserting the n‐ZnO NP layer. By comparing the results of I–V, EL and photoluminescence for LEDs, it can be confirmed that the holes inject from p‐ZnO NP layer to n‐ZnO NP layer and the mechanism of these devices are that of p‐n junction LEDs.