In-situ spatial and temporal electrical characterization of ZnO thin films deposited by atmospheric pressure chemical vapour deposition on flexible polymer substrates

Abstract

A technique is presented for collecting data on both the spatial and temporal variations in the electrical properties of a film as it is deposited on a flexible substrate. A flexible printed circuit board substrate with parallel electrodes distributed across its surface was designed. Zinc oxide films were then deposited on the flexible substrate at different temperatures via atmospheric pressure chemical vapour deposition (AP-CVD) using a spatial atomic layer deposition system. AP-CVD is a promising high-throughput thin film deposition technique with applications in flexible electronics. Collecting data on the film properties in-situ allows us to directly observe how deposition conditions affect the evolution of those properties in real-time. The spatial uniformity of the growing film was monitored, and the various stages of film nucleation and growth on the polymer substrate were observed. The measured resistance of the films was observed to be very high until a critical amount of material has been deposited, consistent with Volmer–Weber growth. Furthermore, monitoring the film resistance during post-deposition cooling enabled immediate identification of metallic or semiconducting behaviour within the conductive ZnO films. This technique allows for a more complete understanding of metal chalcogen film growth and properties, and the high volume of data generated will be useful for future implementations of machine-learning directed materials science.

Surface Engineering Strategies to Enhance the In Situ Performance of Medical Devices Including Atomic Scale Engineering

“…Figure 26 illustrates two methods for the functioning of passive coating consisting of antimicrobial agents. The incorporation of substance with antimicrobial agents relative to a biomaterial is achievable via surface coating or modifying techniques with advanced strategies such as aniodization [231], thermal spraying [232], atmospheric pressure chemical vapour deposition [233], gel-vapour deposition [234], atomic layer deposition [235], and plasma ionization [236]. Surface engineering techniques help in the fabrication of lightweight and durable fibers.…”

Strain Balanced Self‐Supporting Single‐Crystalline LiNbO3 Thin Films for Flexible Electronics

“…[1] Integrating functional thin films with flexible polymer substrates is an effective way to achieve flexibility of electronic devices. [2][3] However, due to by metal-organic chemical vapor deposition, [36] molecular beam epitaxy, [37] RF-sputtering, [38] sol-gel method, [39] or et al, are polycrystalline or even amorphous. On the other hand, due to the internal stress induced by the implanted ions, the LN thin films prepared by ion slicing process usually become deformed when released.…”

“…[ 1 ] Integrating functional thin films with flexible polymer substrates is an effective way to achieve flexibility of electronic devices. [ 2–3 ] However, due to the chemical and mechanical incompatibility (e.g., lattice and thermal expansion mismatches) at the interface of dissimilar materials, [ 4–5 ] it is difficult to synthesize high‐quality, especially single‐crystalline functional films directly on polymer substrates. Various lift‐off and layer transfer technologies have been developed to monolithic integration of highly mismatched material systems for the demands of modern electronic and photonic devices, including epitaxial lift‐off, [ 6 ] mechanical spalling, [ 7 ] laser lift‐off, [ 8 ] and 2D material‐assisted layer transfer.…”

Highly Sensitive Self-Actuated Zinc Oxide Resonant Microcantilever Humidity Sensor

“…ZnO is a versatile gas-sensor receptor material that has been employed in a variety of unique gas-sensor devices, such as chemiresistive, − resonant microcantilever, − , and quartz crystal microbalance (QCM) type sensors. − It can serve as the cantilever structural layer because of its comparable elastic modulus to silicon. − Moreover, its deposition by AP-SALD and growth behavior at atmospheric pressures (i.e., open-air) are well understood. − Utilizing AP-SALD and other conventional fabrication techniques ensures reproducibility of the produced cantilever device at scale. The reduction in cantilever thickness to the nanoscale reduces its overall mass, making it more susceptible to small mass changes via gas adsorption.…”

“…A 200 nm-thick ZnO layer (Figure c) was deposited in open-air conditions by a custom-built AP-SALD system, which employs a close-proximity reactor head configuration previously described elsewhere. − Diethylzinc and water were used as the zinc and oxygen precursors, respectively. Nitrogen was used as a carrier gas to deliver the precursor vapors from liquid sources to the reactor head.…”