Applications for organic field effect transistors (OFET)
OFETs are used for various applications, including flexible displays, smart sensors, organic photovoltaics and printed electronics.
Silicon-based OFET substrates provide a high-precision patterned foundation for the fabrication of organic field-effect transistors (OFETs) and allow the deposition of organic semiconductor layers that determine the electronic properties of the OFET. The resulting OFETs can be flexibly designed due to the adaptability of the materials as well as source and drain contacts.
Due to their reliability and reproducible preparation, these substrates are used worldwide by all major developers of organic semiconductor materials as part of standardized material monitoring.
The Si bulk acts as gate electrode and controls the current flow between the source and drain gold electrodes. A suitably doped Si-SiO2 interface in CMOS quality guarantees a reproducible gate contact. The gold electrodes with patented adhesive layer suppress the formation of injection barriers between the gold electrodes and the organic in the transistor channel, even for p-type semiconductors, so that reliable ohmic source / drain contacts are formed in the back-gated OFET.
In the standard layout, 60 chips of size 15 × 15 mm² each with a total of 960 individual transistor structures are realized on 200 mm wafers. Each chip contains four groups of four identical transistors with channel lengths of 2.5, 5, 10 and 20 µm. Identical layouts with graduated channel widths as well as the flexible choice of oxide thickness allow adaptation to a wide voltage and conductivity range of the materials under investigation. Customized layouts with modified electrode geometry are possible at any time.