Dramatic enhancement of 1.54μm emission in Er doped GaN quantum well structures

摘要

Erbium (Er) doped Ⅲ-nitride materials have attracted much attention due to their capability to provide highly thermal stable optical emission in the technologically important as well as eye-safer 1540nm wavelength window. There is a continued need to exploring effective mechanisms to further improve the quantum efficiency (QE) of the 1.54 μm emission in Er-doped Ⅲ-nitrides. GaN/ AlN multiple quantum wells (MQWs:Er) have been synthesized by metal organic chemical vapor deposition and explored as an effective means to improve the QE of the 1.54 μm emission via carrier confinement and strain engineering. The 1.54 μm emission properties from MQWs:Er were probed by photoluminescence (PL) emission spectroscopy. It was found that the emission intensity from MQWs:Er is 9 times higher than that of GaN:Er epilayers with a comparable Er active layer thickness. The influences of the well and barrier width on the PL emission at 1.54 μm were studied. The results revealed that MQWs:Er consisting of well width between 1 and 1.5 nm and the largest possible barrier width before reaching the critical thickness provide the largest boost in QE of the 1.54 μm emission. These results demonstrate that MQWs:Er provide a basis for efficient photonic devices active at 1.54 μm.