Formation of Sb-Doped SnO[sub 2] p-Type Ohmic Contact for Near-UV GaN-Based LEDs by a CIO Interlayer

Abstract

A Cu-doped In 2 O 3 (CIO) interlayer was introduced to enhance the electrical and optical properties of Sb-doped SnO 2 (ATO) p-type electrodes grown by pulsed laser deposition. CIO (2.5 nm)/ATO (250 nm) contacts become ohmic with specific contact resistance of 2.1 × 10 -3 Ω cm 2 and give transmittance of ∼81% at 400 nm, when annealed at 630°C for 1 min in air. Near-UV (400 nm) GaN-based light-emitting diodes (LEDs) fabricated with the CIO/ATO p-electrodes give forward-bias voltage of 3.91 V at injection current of 20 mA and show much higher output power compared to LEDs with conventional Ni/Au p-electrodes.