Organic‐Single‐Crystal Vertical Field‐Effect Transistors and Phototransistors

Many advanced materials have been developed for organic field-effect transistors (OFETs) or thin-film transistors (TFTs) based on organic and organic hybrid materials. However, although many new OFETs exhibit superior characteristic parameters (such as high mobility), most of them show nonideal performances that have strongly limited progress in the design of molecules, the understanding of transport mechanisms, and the circuit applications of OFETs. In this review, the device physics of ideal and nonideal OFETs is discussed first to understand the factors that limit effective mobility in semiconducting channels, distort the potential distribution, or reduce the drift electric field. Then, recent advances in optimizing the material combinations, device structures, and fabrications of OFETs toward ideal transistors are discussed. Based on the good control of materials and interfaces, some new and novel concepts to utilize the nonideal properties of OFETs to build low-power circuits and integrated sensors are also discussed.

Section: Utilizations Of Nonideal Ofetsmentioning

confidence: 99%

Understanding, Optimizing, and Utilizing Nonideal Transistors Based on Organic or Organic Hybrid Semiconductors

Yang

Dai

et al. 2019

Section: Vertical Organic Light-emitting Transistors (Volets)mentioning

confidence: 99%

“…Among the various organic solid states, organic semiconductor single crystals (OSSCs) have attractive advantages of long-range molecular orders and low-density defects, no grain boundaries, which have been the best candidates for fundamental studies and construction of high performance organic electronic/optoelectronic devices and circuits. [29] This device fabrication process can be simply divided into five steps: a) desired substrate with CVD graphene layer transferred from copper foil under the assistance of PMMA method; b) patterned graphene arrays achieved first with aluminum as mask and then removing them via nitric acid to be used as the source electrode; c) followed with deposition of gold electrodes on the pre-patterned graphene arrays in order for easy measurement; d) transferring the desirable OSSCs onto the graphene as active layers; e) finally depositing the gold drain electrodes on organic semiconductor layer via a mechanical transfer technique approach to make a softcontact between top electrode and organic active layer. [134][135][136][137][138][139] Compared with planar phototransistors, vertical phototransistors will give much higher performances with more efficient separation of photogenerated excitons into electrons and holes and fast response rate due to their intrinsically much shorter channel lengths.…”

Section: Vertical Field-effect Phototransistorsmentioning

confidence: 99%

“…In addition, more attention should be paid to VOFETs from various fields such as material sciences, device physics, and device engineering, etc. [29] Copyright 2018, Wiley-VCH. Currently the preparation of large-size and ultrathin 2D OSSCs provide us a good platform and opportunity for investigation of organic integrated electronic and optoelectronic devices.…”

Section: Outlook and Conclusionmentioning

confidence: 99%

“…When the gate voltage is applied, it can generate opposite carriers in the thin organic semiconductor layer adjacent to the dielectric layer and tune the density of charge carriers, thus realizing the modulation of source-drain current in transistors. [29] In addition, in view of the thin geometry and unique charge transport direction, VOFETs also afford practical applications in flexible devices because the formation of small cracks or dislocations in channel layer has little effect on charge transport performance under repeated bending cycles. Although there are numerous publications regarding planar OFETs and significant advances have been achieved, [22,23] an inherent disadvantage of planar OFETs is their relatively larger conducting channels (usually in micrometers or even much larger scales).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Vertical Organic Field‐Effect Transistors

Liu

Qin

Gao

et al. 2019

Self Cite

Field-effect transistors are the fundamental building blocks for electronic circuits and processors. Compared with inorganic transistors, organic field-effect transistors (OFETs), featuring low cost, low weight, and easy fabrication, are attractive for large-area flexible electronic devices. At present, OFETs with planar structures are widely investigated device structures in organic electronics and optoelectronics; however, they face enormous challenges in realizing large current density, fast operation speed, and outstanding mechanical flexibility for advancing their potential commercialized applications. In this context, vertical organic field-effect transistors (VOFETs), composed of vertically stacked source/drain electrodes, could provide an effective approach for solving these questions due to their inherent small channel length and unique working principles. Since the first report of VOFETs in 2004, impressive progress has been witnessed in this field with the improvement of device performance. The aim of this review is to give a systematical summary of VOFETs with a special focus on device structure optimization for improved performance and potential applications demonstrated by VOFETs. An overview of the development of VOFETs along with current challenges and perspectives is also discussed. It is hoped that this review is timely and valuable for the next step in the rapid development of VOFETs and their related research fields.

A Centrosymmetric Organic Semiconductor with Donor–Acceptor Interaction for Highly Photostable Organic Transistors

Zhang

Chen

et al. 2022

Self Cite

Molecule design of organic semiconductors (OSCs) for eliminating photoresponse and maintaining high charge mobility concurrently is beneficial to realize intrinsically photostable and high‐performance organic field‐effect transistors (OFETs), which has never been reported. Here, a novel organic semiconductor TFP‐TT‐TPA with a centrosymmetric structure is synthesized. Remarkably, OFETs with TFP‐TT‐TPA show negligible photoresponse under light intensity up to 170.4 mW cm−2 (higher than sunlight intensity, about 138 mW cm−2), which ensures that the devices can work stably under sunlight. Through the single‐crystal structure and exciton dynamics analysis, it is found that the specific structure design can make strong intermolecular D–A interaction that occurs in the aggregate state, which facilitates the process of exciton quenching and thus enables the photostable OFETs. This study provides a new strategy for the design of organic semiconductors with intrinsic photostability and the construction of photostable organic optoelectronic devices for applications in light environment.