has been expanded in the recent years owing to the unique properties of organic materials, such as biodegradability [11,12] and stretchability. [13][14][15] This allows for easier access to useful unobtained information that has not been extracted by conventional silicon technology. Flexible electronic devices often require integrated circuits (ICs) for signal processing; thus, the development of flexible ICs is crucial in the practical applications of flexible electric devices.Organic thin-film transistors (OTFTs) are attractive candidates in the development of flexible ICs because they can be fabricated on flexible, and even stretchable substrates, with low-cost and largearea fabrication processes. [16][17][18] Their individual electric properties have been analyzed and reported over the past few decades, focusing on threshold voltage (V th ), [19][20][21][22][23][24][25][26][27][28] mobility, [29][30][31] and stability, [32,33] which were primarily controlled or improved by modulating the behavior of charge carriers at the interface between the gate dielectrics and semiconductors. Particularly, V th is one of the key characteristics which affects the performance of the ICs considering that in the early stages the silicon-based ICs was produced using only V th controlled n-channel transistors. [34] Therefore, the V th control using charge-carrier modulation is essential in OTFTs as well as silicon transistors.To maximize the performance metrics of the ICs, for example, the reliability, amplification gain, and operation Flexible electronics have gained considerable attention for application in wearable devices. Organic transistors are potential candidates to develop flexible integrated circuits (ICs). A primary technique for maximizing their reliability, gain, and operation speed is the modulation of charge-carrier behavior in the respective transistors fabricated on the same substrate. In this work, heterogeneous functional dielectric patterns (HFDP) of ultrathin polymer gate dielectrics of poly((±)endo,exo-bicyclo[2.2.1]hept-ene-2,3-dicarboxylic acid, diphenylester) (PNDPE) are introduced. The HFDP that are obtained via the photo-Fries rearrangement by ultraviolet radiation in the homogeneous PNDPE provide a functional area for charge-carrier modulation. This leads to programmable threshold voltage control over a wide range (−1.5 to +0.2 V) in the transistors with a high patterning resolution, at 2 V operational voltage. The transistors also exhibit high operational stability over 140 days and under the bias-stress duration of 1800 s. With the HFDP, the performance metrics of ICs, for example, the noise margin and gain of the zero-V GS load inverters and the oscillation frequency of ring oscillators are improved to 80%, 1200, and 2.5 kHz, respectively, which are the highest among the previously reported zero-V GS -based organic circuits. The HFDP can be applied to much complex and ultraflexible ICs.
Tip-enhanced Raman spectroscopy (TERS) has been recognized as a useful tool for nanoscale chemical analysis, and it can further reach down to the sub-nanometer scale in the gap-mode configuration. Using an atomic force microscopy (AFM) in gap-mode TERS for position control of a metallic tip, a unique and correlative analysis can be even realized at the single molecule level. However, one of crucial issues in AFM-based gap-mode TERS is the fabrication of reliable and reproducible cantilver metallic tips. Here, we propose a simple, cost-effective fabrication method of metal-coated tips for AFM-based gap-mode TERS by means of the physical vapor deposition technique in a reproducible way. Our plamonic tips have extremely smooth silver layers on one side of the pyramidal tip, which is totally different from the regular metallic tips that hold granular metallic structures randomly arranged on their bodies. Importantly, all fabricated tips exhibited a reasonably high enhancement factor of more than 104, which indicates that the reproducibility of our plasmonic tip is virtually 100% in the gap-mode configuration. The excellent reproducibility of gap-mode TERS measurement holds great promise for rendering AFM-based TERS as a powerful analytical technique in a broad range of fields.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.