Ag composition gradient CuCr0.93Mg0.07O2/Ag/CuCr0.93Mg0.07O2 coatings with improved p-type optoelectronic performances

The optoelectronic properties of Mg-doped CuCrO2 with delafossite structure were enhanced by stacking CuCr0.93Mg0.07O2/Ag/CuCr0.93Mg0.07O2 multilayers. The influences of the deposition time of the Ag and the thickness of the CuCr0.93Mg0.07O2 layers on the film’s performance were investigated. When the stacks were deposited under our deposition conditions, no continuous Ag layer was observed. The diffusion of Ag atoms into the neighboring CuCr0.93Mg0.07O2 layers caused a composition gradient of Ag in the films and caused Cr3+ cations to be replaced by Ag+ cations, which is beneficial for improving the conductivity of the films. When the Ag deposition time was increased, Schottky barriers occurred between Ag nanocrystallites and CuCr0.93Mg0.07O2 grains, lowering the films’ optoelectronic performances. The multilayers’ optoelectronic performances were enhanced when the thickness of the CuCr0.93Mg0.07O2 layers was decreased. Optimal films with a relatively high figure of merit of 2.37 × 10−7 Ω−1 can be achieved when the deposition time of Ag and the thickness of CuCrO2:Mg layers are optimized.