Interface Analysis of CuO/ZnO Heterojunction for Optoelectronic Applications: An Experimental and Simulation Study

Material interfaces are essential building blocks for a wide variety of emerging technologies. Well‐defined and optimized heterostructures serve as the foundation for developing materials toward innovative optoelectronic applications. The distinctive features of heterojunctions have recently attracted the attention of the optoelectronics community, prompting a rise in the construction of modern devices. A solution‐based method is presented for developing a heterojunction made of copper oxide nanorods coated with zinc oxide thin films. Coating ZnO thin films on vertically oriented CuO nanorods results in the development of ZnO/CuO heterojunction configuration, which exhibits outstanding optoelectronic capabilities like broadband absorption and white light emission. Additionally, systematic ab initio computations have been done to comprehend the impact on various optical and electrical properties. It is observed that defects play a very crucial role in determining the quantum efficiency as well as improved visible to near‐infrared absorption. Moreover, the formation of energy levels near conduction bands in the presence of vacancies leads to broad absorption in the ultraviolet–visible region, and therefore, greater than 60% quantum efficiency over the range 350–800 nm is observed. Therefore, the presented work serves as the foundation for additional design and optimization techniques for oxide heterojunctions and emerging applications. This work evaluates the physical, optical, and interface properties of the ZnO/CuO heterostructure. The presence of vacancies results in the formation of various energy levels with broad ultraviolet–visible absorption range leading to the quantum efficiency of greater than 60% in the wavelength range from 350 to 800 nm. Consequently, the heterojunction serves as a broadband detector.