Fig. 3From: Highly Sensitive and Stable SERS Substrate Fabricated by Co-sputtering and Atomic Layer DepositionSEM images of Ag NPs prepared on glass slides at 1:1 power rate with different (Ag, Al) co-sputtering time (a–c) indicated (30 s, 60 s, 90 s, respectively) and at 60 s with different (Ag, Al) power ratio (d–f) indicated (4:1, 2:1, 1:2 respectively)Back to article page