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Abstract: We report on the formation of reflective and low resistance Ag-based contacts to p-GaN using Ir interlayers for GaN-based near UV flip-chip light emitting diodes (FCLEDs). The as-deposited Ir/Ag contacts give non-linear current–voltage (I–V) behaviors. However, the contacts become ohmic with specific contact resistance of ∼10−4 Ωcm2 when annealed at temperatures 330–530°C for 1min in air. The 530°C-annealed Ir/Ag contacts give a reflectance of ∼75% at a wavelength of 405nm, which is somewhat higher than that (∼71%) of annealed single Ag contacts. It is also shown that the output power of the LEDs made with the annealed Ir/Ag contact is higher than that with the annealed single Ag contact. [Copyright &y& Elsevier]

Abstract: MgZnO(MZO) interlayers are introduced to form high-quality Ag-based ohmic contacts to p-type GaN (N a =4×1017 cm−3) for GaN-based flip-chip light-emitting diodes (LEDs). The MZO (2.5nm)/Ag (250nm) contacts become ohmic with specific contact resistance of 3.83×10−4 Ωcm2 and reflectance of ∼83% at a wavelength of 405nm when annealed at 530°C for 1min in air. It is shown that LEDs made with the MZO interlayers yield reverse leakage currents three orders of magnitude lower than that of LEDs without the interlayers. In addition, the LEDs fabricated with the MZO interlayers show higher output power as compared with the LEDs without the interlayers. [Copyright &y& Elsevier]

Abstract: We report on the improvement of the electrical characteristics of GaN-based light-emitting diodes (LEDs) fabricated with Ag (1nm)/indium tin oxide (ITO) (250nm) p-type contacts by using Ni nanodots. As-deposited Ag/ITO contacts with and without the Ni nanodots give non-linear electrical behaviour. However, annealing the samples at 530–630°C for 1min in air results in ohmic behaviour. The reverse leakage current characteristics of near UV LEDs are much improved when the Ni nanodots are used. The output power (at 20mA) of LEDs fabricated with the Ni nanodots is enhanced by a factor of 1.34 as compared with that of LEDs made without the Ni nanodots. [Copyright &y& Elsevier]