Effects of porosity on the structural and optoelectronic properties of Er-doped Ga2O3 epitaxial films on etched epi-GaN/sapphire substrates

The nanoporous (NP) GaN wafers which were fabricated by electrochemical etching (EC) method were used as substrates to deposit Er-doped Ga2O3 epitaxial films by pulsed layer deposition (PLD). The epitaxial relationship between the GaN and Er doped beta-Ga2O3 film was Ga2O3 (-201) parallel to GaN (0001) with Ga2O3 [010] parallel to GaN [-12-10]. Compared to the Er doped films on the epi-GaN wafers with the porosity of 0%, similar to 20% and similar to 60%, the beta-Ga2O3 film deposited on the wafer with a porosity of similar to 40%, which has an energy bandgap of similar to 4.89 eV, has the best crystal quality and optoelectronic properties. The performance enhancement should be due to improved crystalline quality as a result of the existence of nanopores in the etched substrates. The excellent properties of Er doped Ga2O3 films indicated that the films have great potential to fabricate Ga2O3 optoelectronic devices.

Automated summary

Nanoporous GaN wafers fabricated by electrochemical etching were used as substrates to deposit Er-doped Ga2O3 epitaxial films, which showed excellent crystal quality and optoelectronic properties. The films have great potential for fabricating Ga2O3 optoelectronic devices.