Semi-Transparent p-Cu₂O/n-ZnO Nanoscale-Film Heterojunctions for Photodetection and Photovoltaic Applications

Abstract

Transparent nanoscale-film heterojunctions based on Cu2O and ZnO were fabricated by atomic layer deposition and reactive magnetron sputtering. The constitutive layers exhibit high crystalline quality and a local epitaxial relation between Cu2O and ZnO was achieved with [110] Cu2O || [001] ZnO and [001] Cu2O || [010] ZnO as evidenced by high resolution transmission electron microscopy and. Cu2O films show very low resistivity and high mobility values of 9 -150Ω cm and 19 cm 2 / V s, respectively. The Cu2O/ZnO heterojunctions exhibit a non-linear rectifying behavior characteristic of a p-n junction, self-powered photo-response under 1-Sun illumination and an average transmittance of 73% in the visible region of the electromagnetic spectrum. These results are promising for all-oxide transparent electronics, photodetection and photovoltaic applications.

Composition-driven transition from amorphous to crystalline films enables bottom-up design of functional surfaces

“…Among the many approaches to modify surface properties, thin film deposition has established itself as an important way of materials functionalization with low raw materials consumption, which is highly sought in the current world. Most reported studies rely on the inherent properties of the deposited materials or modification of their microstructure to adjust surface properties [13][14][15]. In this context, physical vapor deposition methods are particularly attractive as they are suited to grow thin layers of almost any material on any other one, e.g.…”

In Situ and Real-Time Nanoscale Monitoring of Ultra-Thin Metal Film Growth Using Optical and Electrical Diagnostic Tools

“…The overall results reviewed in the present article demonstrate that in situ, real-time optical and electrical techniques are powerful tools to monitor thin film growth at the nanoscale and gain insights on the correlation among atomic-scale mechanisms and resulting film morphology. From the view point of applications, these diagnostics could further contribute to optimize the growth of functional nanoscale layers and smart coating technologies relying on the integration of plasmonic devices and transparent electrodes on substrates beyond Si, such as glass, oxides, Van-der-Waals 2D crystals, or polymeric/flexible substrates [ 17 , 146 , 147 , 148 , 152 , 153 , 154 ]. To this end, their implementation may involve some technological improvement/modification of the actual set-up (for instance the curvature of a transparent substrate from laser-based deflectometry can be measured from the substrate backside coated with a reflective layer or by using other types of stress-sensors), as well as refinement of the optical modelling of ellipsometric data (to account for interband transitions in some metallic films, or optical anisotropy of some polymeric substrates).…”

Microwave-Epoxide-Assisted Hydrothermal Synthesis of the CuO/ZnO Heterojunction: a Highly Versatile Route to Develop H2S Gas Sensors

“…This is the basis of unique synergistic effects to the substantial enhancement in the gas response compared with their single component system. 7,8 In the present work, efforts were made to develop the CuO/ ZnO heterojunction using epoxide-assisted sol−gel chemistry in combination with the microwave hydrothermal process. In the state-of-the-art, despite significant investigations on CuO/ ZnO in recent years, 9−15 this is the first ever report that disseminates the results on the epoxide [propylene oxide (PO)]-assisted sol−gel process of the CuO/ZnO heterojunction via a microwave hydrothermal route for H 2 S gassensing proficiency.…”

“…This in turn results in charge transfer and, thereby, the formation of a depletion layer. This is the basis of unique synergistic effects to the substantial enhancement in the gas response compared with their single component system. , …”