Fig. 4From: Two-step deposition of Al-doped ZnO on p-GaN to form ohmic contacts a, b, c, d Surface morphologies of PAD-AZO films (1 μm × 1 μm) at different growth temperatures of 500, 600, 700 and 800 °C, respectively. e the surface morphologies of ALD-AZO film that directly on p-GaN. f the surface topography of two-step deposited AZO filmBack to article page