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New Approach Brings Industry a Step Closer to Transparent ElectronicsApril 8, 2021 | Fleet
Estimated reading time: 3 minutes
A new study could pave the way to revolutionary, transparent electronics.
Such see-through devices could potentially be integrated in glass, in flexible displays and in smart contact lenses, bringing to life futuristic devices that seem like the product of science fiction.
For several decades, researchers have sought a new class of electronics based on semiconducting oxides, whose optical transparency could enable these fully-transparent electronics.
Oxide-based devices could also find use in power electronics and communication technology, reducing the carbon footprint of our utility networks.
A RMIT-led team has now introduced ultrathin beta-tellurite to the two-dimensional (2D) semiconducting material family, providing an answer to this decades-long search for a high mobility p-type oxide.
“This new, high-mobility p-type oxide fills a crucial gap in the materials spectrum to enable fast, transparent circuits,” says team leader Dr Torben Daeneke, who led the collaboration across three FLEET nodes.
Other key advantages of the long-sought-after oxide-based semiconductors are their stability in air, less-stringent purity requirements, low costs and easy deposition.
“In our advance, the missing link was finding the right, ‘positive’ approach,” says Torben.
Positivity Has Been Lacking
There are two types of semiconducting materials. ‘N-type’ materials have abundant negatively-charged electrons, while ‘p-type’ semiconductors possess plenty of positively-charged holes.
It’s the stacking together of complementary n-type and p-type materials that allows electronic devices such as diodes, rectifiers and logic circuits.
Modern life is critically reliant on these materials since they are the building blocks of every computer and smartphone.
A barrier to oxide devices has been that while many high-performance n-type oxides are known, there is a significant lack of high-quality p-type oxides.
Theory Prompts Action
However in 2018 a computational study revealed that beta-tellurite (?-TeO2) could be an attractive p-type oxide candidate, with tellurium’s peculiar place in the periodic table meaning it can behave as both a metal and a non-metal, providing its oxide with uniquely useful properties.
“This prediction encouraged our group at RMIT University to explore its properties and applications,” says Dr Torben Daeneke, who is a FLEET associate investigator.
Liquid Metal – Pathway to Explore 2D Materials
Dr Daeneke’s team demonstrated the isolation of beta-tellurite with a specifically developed synthesis technique that relies on liquid metal chemistry.
“A molten mixture of tellurium (Te) and selenium (Se) is prepared and allowed to roll over a surface,” explains co-first author Patjaree Aukarasereenont.
“Thanks to the oxygen in ambient air, the molten droplet naturally forms a thin surface oxide layer of beta-tellurite. As the liquid droplet is rolled over the surface, this oxide layer sticks to it, depositing atomically thin oxide sheets in its way.”
“The process is similar to drawing: you use a glass rod as a pen and the liquid metal is your ink,” explains Ms Aukarasereenont, who is a FLEET PhD student at RMIT.
While the desirable ?-phase of tellurite grows below 300 °C, pure tellurium has a high melting point, above 500 °C. Therefore, selenium was added to design an alloy that has a lower melting point, making the synthesis possible.
“The ultrathin sheets we obtained are just 1.5 nanometres thick – corresponding to only few atoms. The material was highly transparent across the visible spectrum, having a bandgap of 3.7 eV which means that they are essentially invisible to the human eye” explains co-author Dr Ali Zavabeti.
Assessing Beta-Tellurite: Up to 100 Times Faster
To assess the electronic properties of the developed materials, field-effect transistors (FETs) were fabricated.
“These devices showed characteristic p-type switching as well as a high hole mobility (roughly 140 cm2V-1s-1), showing that beta-tellurite is ten to one hundred times faster than existing p-type oxide semiconductors. The excellent on/off ratio (over 106) also attests the material is suitable for power efficient, fast devices” Ms Patjaree Aukarasereenont said.
“The findings close a crucial gap in the electronic material library,” Dr Ali Zavabeti said.
“Having a fast, transparent p-type semiconductor at our disposal has the potential to revolutionise transparent electronics, while also enabling better displays and improved energy-efficient devices.”
The team plans to further explore the potential of this novel semiconductor. “Our further investigations of this exciting material will explore integration in existing and next-generation consumer electronics,” says Dr Torben Daeneke.
Read the original article, here.
Indium Corporation advisor, and founder/principal of DS&A LLC, Dave Saums will present on innovative thermal materials for semiconductor testing at TestConX 2024, held in Mesa, AZ, March 3-6.
Key Supplier for Mechanical and Optical Processes in the New Teltonika PCB Factory – Schmoll Maschinen GmbH02/14/2024 | Schmoll Maschinen
Schmoll Maschinen is very happy to become the business partner of Teltonika and to become part of one of the biggest projects in the PCB industry in Europe for the last 5 years.
Kerafol and X2F are teaming up to develop state-of-the-art thermal management solutions for electronic devices by leveraging the advantages of Kerafol's thermally conductive materials and X2F's patented controlled-viscosity molding technologies.
Heraeus Electronics, a leading provider of advanced materials solutions, is pleased to announce the successful acquisition of the PriElex electronics inks business line from Kayaku Advanced Materials Inc.
The designer needs to have a working understanding of two key manufacturing operations: basic circuit board fabrication procedures and assembly process practices. For printed circuit board manufacturing, the number of steps required to produce the printed circuit board correlates to the circuit board's complexity. Greater process complexity in fabricating the circuit board equates to increased costs. To develop any portion of the electronic product, the designer must apply the design for manufacturing (DFM) principles established in the industry. In fact, DFM should always be the goal of the design engineer. It encompasses a wide range of disciplines that must be considered during the planning phase of any product.