Correlation between the static and dynamic responses of organic single-crystal field-effect transistors

Abstract

Transistors, the most important logic elements, are maintained under dynamic influence during circuit operations. Practically, circuit design protocols and frequency responsibility should stem from a perfect agreement between the static and dynamic properties. However, despite remarkable improvements in mobility for organic semiconductors, the correlation between the device performances achieved under static and dynamic circumstances is controversial. Particularly in the case of organic semiconductors, it remains unclear whether parasitic elements that relate to their unique molecular aggregates may violate the radiofrequency circuit model. Thus, we herein report the manufacture of micrometre-scale transistor arrays composed of solution-processed organic semiconductors, which achieve near very high-frequency band operations. Systematic investigations into the device geometrical factors revealed that the radiofrequency circuit model established on a solid-state continuous medium is extendable to organic single-crystal field-effect transistors. The validity of this radiofrequency circuit model allows a reliable prediction of the performances of organic radiofrequency devices.

A Critical Outlook for the Pursuit of Lower Contact Resistance in Organic Transistors

“…using similar devices have reported comparably low contact resistances, [36,37] leading to a concomitant enhancement in the on/off current ratio (up to 10 10 ) and the transit frequency (up to 45 MHz). [36] While analyses of the crystal structure suggested that the monolayer C 8 -DNBDT-NW crystals contained a higher density of packing defects that limited the TFT performance compared to the multilayer crystals, an additional factor that was not discussed is that the uppermost layer of the crystals may have degraded due to thermal damage during the deposition of the gold contacts (by thermal evaporation in vacuum). [61] To combat this potentially critical effect, the Chan group implemented mechanically transferred gold contacts gently placed onto large-area monolayer crystals of C 10 -DNTT (Figure 7a).…”

Reconfigurable Multifunctional Ambipolar Polymer‐Blend Transistors with Improved Switching‐Off Capability

“…Complementary metal‐oxide semiconductors (CMOS) logic circuits lay the foundation of modern electronics, where both p‐type (hole transport) and n‐type (electron transport) unipolar transistors are usually obtained by controlled doping of intrinsic semiconductors. [ 1–3 ] However, as the device dimensions decrease the conventional doping process such as ion implantation becomes increasingly difficult, and the batch‐to‐batch discrepancy induces wide distribution of device performance. Moreover, building CMOS logics with discrete p‐ or n‐doped transistors complicates the device manufacturing process and limits the miniaturization of the circuits.…”

Organic Permeable Base Transistors – Insights and Perspectives

“…[ 3 ] Recently, various groups have demonstrated the fabrication of OTFTs with switching operations at a few tens of a megahertz, [ 4–8 ] e.g., Sawada et al. [ 5 ] reported a solution‐processed organic single‐crystal transistor with f T = 45 MHz at 7 V; recently, Perinot et al. [ 8 ] also reported a solution‐processed organic transistor with f T = 160 MHz at 40 V. The recent achievements open a route for high‐frequency OTFTs, but they still need further optimizations in order to go toward industrial production (e.g., fabrication on flexible substrates).…”

“…In the last decade, the OTFT community focused on improving the charge carrier mobility in organic semiconductor materials, which is nowadays in excess of 10 cm 2 V −1 s −1 . [ 3 ] Recently, various groups have demonstrated the fabrication of OTFTs with switching operations at a few tens of a megahertz, [ 4–8 ] e.g., Sawada et al. [ 5 ] reported a solution‐processed organic single‐crystal transistor with f T = 45 MHz at 7 V; recently, Perinot et al.…”