A new electrode design for ambipolar injection in organic semiconductors

Kanagasekaran, Thangavel; Shimotani, Hidekazu; Shimizu, Ryo; Hitosugi, Taro; Tanigaki, Katsumi

doi:10.1038/s41467-017-01047-9

Cited by 43 publications

(49 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the charge‐carrier mobilities for most of the currently available OLETs are still very low, generally below 10 −2 cm 2 V −1 s −1 or even lower when the channel shows highly unbalanced charge mobility, resulting in low current density and a nontunable light‐emission region mainly located in the vicinity of the electrode, especially at the electron‐injection electrodes due to the inefficient injected electrons . In addition, efficiently balanced ambipolar transport with high current density could be achieved for some superior electrical organic semiconductor‐based OLETs, such as rubrene, but the EQE is still very low due to the low luminescence of the active materials. Thus, the use of high‐mobility emissive organic semiconductors is crucial for realizing high‐performance OLETs.…”

Section: Device Applications Of Osscs In Electronics and Photonicsmentioning

confidence: 99%

Organic Semiconductor Single Crystals for Electronics and Photonics

2018

View full text Add to dashboard Cite

Organic semiconducting single crystals (OSSCs) are ideal candidates for the construction of high-performance optoelectronic devices/circuits and a great platform for fundamental research due to their long-range order, absence of grain boundaries, and extremely low defect density. Impressive improvements have recently been made in organic optoelectronics: the charge-carrier mobility is now over 10 cm V s and the fluorescence efficiency reaches 90% for many OSSCs. Moreover, high mobility and strong emission can be integrated into a single OSSC, for example, showing a mobility of up to 34 cm V s and a photoluminescence yield of 41.2%. These achievements are attributed to the rational design and synthesis of organic semiconductors as well as improvements in preparation technology for crystals, which accelerate the application of OSSCs in devices and circuits, such as organic field-effect transistors, organic photodetectors, organic photovoltaics, organic light-emitting diodes, organic light-emitting transistors, and even electrically pumped organic lasers. In this context, an overview of these fantastic advancements in terms of the fundamental insights into developing high-performance organic semiconductors, efficient strategies for yielding desirable high-quality OSSCs, and their applications in optoelectronic devices and circuits is presented. Finally, an overview of the development of OSSCs along with current challenges and future research directions is provided.

show abstract

Section: Device Applications Of Osscs In Electronics and Photonicsmentioning

confidence: 99%

Organic Semiconductor Single Crystals for Electronics and Photonics

2018

View full text Add to dashboard Cite

show abstract

“…The improvement trend held for several other combinations of semiconductors and oxides, suggesting that this strategy can be applied to a variety of devices. Another recently developed bilayer structure incorporates a polycrystalline semiconductor in between a metal electrode and the alkane tetratetracontane (TTC), i.e., a metal/OSC/TTC contact . This method allowed for enhanced hole and electron injection.…”

Section: Reducing Contact Resistance: Electrode Design and Beyondmentioning

confidence: 99%

Contact Resistance in Organic Field‐Effect Transistors: Conquering the Barrier

Waldrip

Jurchescu

Gundlach

et al. 2019

Adv Funct Materials

225

261

View full text Add to dashboard Cite

Organic semiconductors have sparked interest as flexible, solution processable, and chemically tunable electronic materials. Improvements in charge carrier mobility put organic semiconductors in a competitive position for incorporation in a variety of (opto-)electronic applications. One example is the organic field-effect transistor (OFET), which is the fundamental building block of many applications based on organic semiconductors. While the semiconductor performance improvements opened up the possibilities for applying organic materials as active components in fast switching electrical devices, the ability to make good electrical contact hinders further development of deployable electronics. Additionally, inefficient contacts represent serious bottlenecks in identifying new electronic materials by inhibiting access to their intrinsic properties or providing misleading information. Recent work focused on the relationships of contact resistance with device architecture, applied voltage, metal and dielectric interfaces, has led to a steady reduction in contact resistance in OFETs. While impressive progress was made, contact resistance is still above the limits necessary to drive devices at the speed required for many active electronic components. Here, the origins of contact resistance and recent improvement in organic transistors are presented, with emphasis on the electric field and geometric considerations of charge injection in OFETs.semiconductors with superior intrinsic charge transport properties, there is a stringent need to improve the device properties in order to allow organic devices to fulfill their technological prospectives. In the organic semiconductor community, contact resistance (R C ) has come under increased scrutiny as it is apparent that the final device performance is often domi nated by carrier injection, rather than the transport through the semiconductor layer. Contact resistance can impact OFET development in multiple ways. First, if not accounted for, a high contact resistance may lead to inaccurate extraction of the device parameters. Second, any inaccuracies in parameter extraction can have significant consequences on material development, from generating incorrect structure-property relationships to discarding organic semiconductors whose efficient intrinsic electrical properties have been masked by inefficient contacts. Beyond OFET and semiconductor characterization, analog, low power, and high frequency applications require a greater level of device parameter control than has been obtained in typical DC, high-voltage OFETs. For analog applications, e.g., integration of conditioning circuits such as local sense amps for distributed flexible sensor arrays, nonlinearity of the transistor response inhibits proper functioning and limits applicability of common models used to design circuitry. Low power device development for novel materials are hindered by the high voltage turn-on and current suppression in devices with large R C . Considering high-frequency applications, Klauk suggest...

show abstract

“…However, ambipolar charge injection and transport are more challenging due to the usually large HOMO–LUMO gap and electron traps at the dielectric/crystal interface. These issues can be overcome by employing careful crystal growth conditions and preparation protocols (exclusion of air and water) and suitable source–drain electrodes with different work functions (e.g., calcium and gold as shown in Figure a), surface treatment or even electrolyte gating . A good number of light‐emitting organic single crystal transistors were demonstrated over the years .…”

Section: Lateral Single Layer and Ambipolar Lefetsmentioning

confidence: 99%

“…These issues can be overcome by employing careful crystal growth conditions and preparation protocols (exclusion of air and water) and suitable source–drain electrodes with different work functions (e.g., calcium and gold as shown in Figure a), surface treatment or even electrolyte gating . A good number of light‐emitting organic single crystal transistors were demonstrated over the years . Nevertheless, combining really high ambipolar carrier mobilities with high photo‐ and electroluminescence yields poses a challenge, which was only recently overcome with selected molecular crystals …”

Section: Lateral Single Layer and Ambipolar Lefetsmentioning

confidence: 99%

Recent Developments and Novel Applications of Thin Film, Light‐Emitting Transistors

Zaumseil

2019

Adv Funct Materials

View full text Add to dashboard Cite

Light-emitting field-effect transistors (LEFETs) combine switching and amplification with light emission and thus represent an interesting optoelectronic device. They are not limited anymore to a few examples and specific materials but are nearly universal for a wide range of semiconductors, from organic to inorganic and nanoscale. This review introduces the basic working principles of lateral unipolar and ambipolar LEFETs and discusses recent examples based on various solution-processed semiconducting materials. Applications beyond simple light emission are presented and possible future directions for lightemitting transistors with added functionalities are outlined. The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adfm.201905269.thus excluding vertical LEFETs, which have been demonstrated for some organic emitter systems. [5][6][7] We will start with LEFETs that do not rely on the injection of both holes and electrons in a single semiconducting layer but show unipolar charge transport and may include multiple semiconducting layers. This short section will be followed by an overview of truly ambipolar single-layer LEFETs, the different possible working principles and various emissive semiconductors with their advantages and drawbacks. The review will conclude with recent examples of LEFET applications that go beyond simple light-emission and take advantage of specific device properties to add functionalities that are difficult to achieve with other optoelectronic devices.

show abstract

A new electrode design for ambipolar injection in organic semiconductors

Cited by 43 publications

References 31 publications

Organic Semiconductor Single Crystals for Electronics and Photonics

Organic Semiconductor Single Crystals for Electronics and Photonics

Contact Resistance in Organic Field‐Effect Transistors: Conquering the Barrier

Recent Developments and Novel Applications of Thin Film, Light‐Emitting Transistors

Contact Info

Product

Resources

About