ZnO p–n Homojunction Random Laser Diode Based on Nitrogen‐Doped p‐type Nanowires

Abstract

An electrically pumped ZnO homojunction random laser diode based on nitrogen‐doped p‐type ZnO nanowires is reported. Nitrogen‐doped ZnO nanowires are grown on a ZnO thin film on a silicon substrate by chemical vapor deposition without using any metal catalyst. The p‐type behavior is studied by output characteristics and transfer characteristic of the nanowire back‐gated field‐effect transistor, as well as low‐temperature photoluminescence. The formation of the p–n junction is confirmed by the current–voltage characteristic and electron beam‐induced current. The nanowire/thin‐film p–n junction acts as random laser diode. The random lasing behavior is demonstrated by using both optical pumping and electrical pumping, with thresholds of 300 kW/cm2 and 40 mA, respectively. The angle‐dependant electroluminescence of the device further proves the random lasing mechanism. An output power of 70 nW is measured at a drive current of 70 mA.