Improvement of the electroluminescence performance from Er-doped Al2O3 nanofilms by insertion of atomic Ga2O3 layers

Abstract

Metal-oxide-semiconductor light-emitting devices (MOSLEDs) based on erbium doped Al2O3 nanofilms still suffer from insufficient and unstable electrical injection. Here, Al2O3/Ga2O3:Er nanolaminate films are fabricated by atomic layer deposition on silicon, in which the insertion of atomic Ga2O3 layers greatly improves the tolerance to the electric field and electron injection of the Al2O3:Er MOSLEDs, thus leading to the outstanding electroluminescence (EL) performance. The maximum injection current is raised from 0.21 A/cm2 up to 1.05 A/cm2 with the optical power density reaching 10.23 mW/cm2. Much higher excitation efficiencies are also achieved with an external quantum efficiency of 14.2% and a power efficiency of 0.16%. Moreover, the operation time of the prototype Al2O3/Ga2O3:Er MOSLEDs is enhanced 21 times compared with the devices without Ga2O3. In addition, the Al2O3/Ga2O3:Er nanolaminate devices can realize EL under alternating-current excitation. This work supplies a promising route to improve the EL performance of rare earth doped Al2O3 nanofilms for the applications in optoelectronics.