Postannealing Effect at Various Gas Ambients on Ohmic Contacts of Pt/ZnO Nanobilayers toward Ultraviolet Photodetectors

Figure 3

In-plane and out-of-plane field emission scanning electron microscopy images for ZnO (0002) thin films synthesized with gas flow rate ratios of DEZn to CO₂ of (a) 1 : 1, (b) 1 : 2, and (c) 1 : 3; the corresponding AFM images (1 × 1 𝜇m²) with gas flow rate ratios of (d) 1 : 1, (e) 1 : 2, and (f) 1 : 3, respectively.