Improved performance of GaN based light emitting diodes with ex-situ sputtered AlN nucleation layers

• Main Authors: Shuo-Wei Chen, Heng Li, Tien-Chang Lu
• Format: Article
• Language: English
• Published: AIP Publishing LLC 2016-04-01
• Series: AIP Advances
• Online Access: http://dx.doi.org/10.1063/1.4947299

The crystal quality, electrical and optical properties of GaN based light emitting diodes (LEDs) with ex-situ sputtered physical vapor deposition (PVD) aluminum nitride (AlN) nucleation layers were investigated. It was found that the crystal quality in terms of defect density and x-ray diffraction linewidth was greatly improved in comparison to LEDs with in-situ low temperature GaN nucleation layer. The light output power was 3.7% increased and the reverse bias voltage of leakage current was twice on LEDs with ex-situ PVD AlN nucleation layers. However, larger compressive strain was discovered in LEDs with ex-situ PVD AlN nucleation layers. The study shows the potential and constrain in applying ex-situ PVD AlN nucleation layers to fabricate high quality GaN crystals in various optoelectronics.