We use silicon/silicon oxide substrates with thermally evaporated gold electrodes. Our standard prefabricated substrates are supplied in batches of ten and fabricated using our High Density OFET system; see schematics below for details.
The prefabricated high-density OFET test chips are recommended for the collection of statistical data after the experimental parameters have been optimised. Create up to 20 OFETs from a single thin film. Simply spin on your semiconductor and quickly wipe between the devices to isolate them before testing with our high-density OFET test board.
A surface passivation treatment is recommended in order to achieve the best results with these bottom-contact, bottom-gate devices. There is a surface treatment procedure detailed in the User Manual for your convenience.
All devices are made to order, so the lead time is up to 2 weeks for standard devices. We can also fabricate the patterns onto other substrate materials for your individual research requirements, so please contact us to discuss your needs.
If you are uncertain about which range of specifications best suits your needs, please contact us to speak to one of our technical support team.
| Productcode | Channelgeometry | Channelwidth | Channellength | OTS/PFBTtreatment | Quantity | Price |
| S221 | Linear | 1 mm | 30 μm | No | 10 | £549 |
| S223 | Linear | 1 mm | 30 μm variable | No | 10 | £549 |
| S233* | Interdigitated | 18 mm | 50 μm | No | 10 | £549 |
Datasheet
Ossila High Density Substrates feature 20 OFETs which can benefit your research in a number of ways. Firstly, production cost is reduced as a result of a higher volume of OFETs per substrate compared to the low density equivalents. This can help to stretch your budget to allow you to produce and test larger numbers of OFETs.
Secondly, producing OFETs is a far faster and less laborious process. Fabrication time is reduced by up to 50% when using prefabricated high density OFETs, freeing up more time to test the devices. As a result of this, greater volumes of statistics can be produced which in turn can provide more robust and reliable research.
Furthermore, OFET variability is reduced since a larger number of OFETs are produced with each fabrication. At Ossila we have optimised the fabrication process in order to produce consistently high quality substrates. In this respect, using our prefabricated substrates rather than fabricating your own can help you to gather more reliable data to benefit your research project.
Prefabricated high density substrates are ideal for mobility testing as they enable swift, efficient testing of high volumes of OFETs. The Ossila high-density OFET test board has been designed for this purpose.
Rather than using a mechanical probe station to test OFETs, which is a delicate and time-consuming process, the high density test board allows testing of multiple OFETs at one time; simply drop the substrate into the test slot, secure the push-fit lid and connect the board via its BNC connectors to an array of test equipment.
The board has been intelligently designed to reduce external noise, leakage current and stray capacitance in order to provide reliable and precise low-current testing.
Specifications
We fabricate p-doped silicon substrates with an insulating 300 nm silicon oxide top layer. Gold is then thermally evaporated on top to produce gate electrodes which also cover the conductive edge of the substrate. It is therefore essential that the edge of the substrate is conductive and not covered with the silicon oxide layer. If not, the silicon oxide must be scratched off the sides of the substrates before it can be used.
At Ossila we have optimised the fabricating process to ensure that the edges are conductive and the substrate immediately ready to use.
We fabricate our high-density substrates with 1-2 nm chromium and 60-70 nm gold. The chromium acts as an adhesion layer to ensure the gold remains firmly attached to the silicon substrate.
One of the most difficult parts of substrate preparation is the OTS treatment; a small amount of moisture must be present to create a smooth monolayer, but too much moisture can result in a rough surface. After extensive research we have optimised this process in our labs and can therefore offer substrates pre-treated with OTS to accelerate your research program even further.
For individual details and dimension drawings of each substrate type see below.
Linear 1 mm x 30 µm constant channel length substrate (S221)
| Geometry | Linear |
| Arrangement | 20 identical OFETs |
| Channel width | 1 mm |
| Channel length | 30 µm |
Linear 1mm x 30 µm variable channel length substrate (S223)
| Geometry | Linear |
| Arrangement | 20 OFETs, 5 channel widths (4 of each width) |
| Channel width | 1 mm |
| Channel length | 30, 40, 50, 60 and 80 µm |
Interdigitated 18 mm x 50 µm constant channel length substrate (S233)
| Geometry | Interdigitated |
| Arrangement | 20 identical OFETs |
| Channel width | 18 mm |
| Channel length | 50 µm |
To the best of our knowledge the technical information provided here is accurate. However, Ossila assume no liability for the accuracy of this information. The values provided here are typical at the time of manufacture and may vary over time and from batch to batch.
About Ossila Founded in 2009 by organic electronics research scientists, Ossila aims to provide the components, equipment, and materials to enable intelligent and efficient scientific research and discovery. Over a decade on, we're proud to supply our products to over 1000 different institutions in over 80 countries globally. With decades of academic and industrial experience in developing organic and thin-film LEDs, photovoltaics, and FETs, we know how long it takes to establish a reliable and efficient device fabrication and testing process. As such, we have developed coherent packages of products and services - enabling researchers to jump-start their organic electronics development program. The Ossila Guarantee Free Worldwide Shipping Eligible orders ship free to anywhere in the world Fast Secure Dispatch Rapid dispatch on in-stock items via secure tracked courier services Quality Assured Backed up by our free two year warranty on all equipment Clear Upfront Pricing Clear pricing in over 30 currencies with no hidden costs Large Order Discounts Save 8% on orders over $10,300.00 and 10% on orders over $12,900.00 Expert Support Our in-house scientists and engineers are always ready to help Trusted Worldwide Great products and service. Have already recommended to many people. Dr. Gregory Welch, University of Calgary Wonderful company with reasonably priced products and so customer-friendly! Shahriar Anwar, Arizona State University The Ossila Team Prof. David Lidzey - Chairman As professor of physics at the University of Sheffield, Prof. David Lidzey heads the university’s Electronic and Photonic Molecular Materials research group (EPMM). During his career, David has worked in both academic and technical environments, with his main areas of research including hybrid organic-inorganic semiconductor materials and devices, organic photonic devices and structures and solution processed photovoltaic devices. Throughout his academic career, he has authored over 220 peer-reviewed papers. Dr. James Kingsley - Managing Director James is a co-founder and managing director of Ossila. With a PhD in quantum mechanics/nanotech and over 12 years’ experience in organic electronics, his work on the fabrication throughput of organic photovoltaics led to the formation of Ossila and the establishment of a strong guiding ethos: to speed up the pace of scientific discovery. James is particularly interested in developing innovative equipment and improving the accessibility of new materials for solution-processable photovoltaics and hybrid organic-inorganic devices. Dr. Alastair Buckley - Technical Director Alastair is a lecturer of Physics at the University of Sheffield, specialising in organic electronics and photonics. He is also a member of the EPMM research group with a focus on understanding and applying the intrinsic advantages of functional organic materials to a range of optoelectronic devices. Alastair’s experience has not been gained solely in academia; he previously led the R&D team at MicroEmissive Displays and therefore has extensive technical experience in OLED displays. He is also the editor and contributor of "Organic Light-Emitting Diodes" by Elsevier. Our Research Scientists Our research scientists and product developers have significant experience in the synthesis and processing of materials and the fabrication and testing of devices. The vision behind Ossila is to share this experience with academic and industrial researchers alike, and to make their research more efficient. By providing products and services that take the hard work out of the device fabrication process, and the equipment to enable accurate, rapid testing, we can free scientists to focus on what they do best - science. Customer Care Team The customer care team is responsible for the customer journey at Ossila. From creating and providing quotes, through to procurement and inventory management, the customer care team is devoted to providing first class customer service. The general day to day responsibilities of a customer care team member involves processing customers orders and price queries, answering customer enquiries, arranging the shipment of parcels and notifying customers of updates on their orders. Collaborations and Partnerships Please contact the customer care team for all enquires, including technical questions about Ossila products or for advice on fabrication and measurement processes. Location and Facilities Ossila is based at the Solpro Business Park in Attercliffe, Sheffield. We operate a purpose-built synthetic chemistry and device testing laboratory on site, where all of our high-purity, batch-specific polymers and other formulations are made. This is complemented by a dedicated suite of thin-film and organic electronics testing and analysis tools within the device fabrication cluster housed in a class 1000 cleanroom in the EPSRC National Epitaxy Facility in Sheffield. All our electronic equipment is manufactured on-site.
