Optical and electrical characteristics of HfO2/Cu40Ag60/HfO2 films prepared by pulsed laser deposition

Hafnium oxide (HfO2) multilayer films were prepared on a glass substrate by pulsed laser deposition, and a novel middle metal layer of Cu40Ag60 was developed. The influence of CuAg thickness and substrate temperature on structural, optical, electrical and morphological characteristics of HfO2/CuAg/HfO2 films were carefully investigated. Multilayer films with different CuAg thickness deposited at room temperature exhibit amorphous structures. As the CuAg thickness varies from 4 to 24 nm, the visible transmittance is kept between 63 and 80%, while the near-infrared transmittance and sheet resistance undergo significant reduction. Increasing the substrate temperature from 100 degrees C to 350 degrees C induces the transformation of HfO2 from amorphous to the crystalline structure, while the near-infrared transmittance and sheet resistance gradually increase. HfO2(50 nm)/CuAg(16 nm)/HfO2(50 nm) multilayer film grown at 150 degrees C exhibits optimal optical and electrical properties with the transmittance of 78.2% in the visible region, 17.7% in the near-infrared region, sheet resistance of 8.59 Omega/square and the highest figure of merit of 1.09 x 10(-2) Omega(-1), which are useful for their potential application in the field of heat mirror and optoelectronics. Furthermore, the possible mechanisms involved in obtaining low infrared transmittance and reduced sheet resistance were explored.

Automated summary

HfO2 multilayer films with CuAg middle metal layer were prepared and investigated for their structural, optical, electrical, and morphological characteristics. The thickness of CuAg and substrate temperature were found to affect the properties of the films. Increasing CuAg thickness resulted in reduced near-infrared transmittance and sheet resistance. Raising the substrate temperature caused a transformation of HfO2 from amorphous to crystalline structure, leading to increased near-infrared transmittance and sheet resistance. The HfO2(50 nm)/CuAg(16 nm)/HfO2(50 nm) multilayer film grown at 150 degrees C exhibited the optimal optical and electrical properties.