Tuning the Dirac Point in CVD-Grown Graphene through Solution Processed n-Type Doping with 2-(2-Methoxyphenyl)-1,3-dimethyl-2,3-dihydro-1<i>H</i>-benzoimidazole

Wei, Peng; Liu, Nan; Lee, Hye Ryoung; Adijanto, Eric; Ci, Lijie; Naab, Benjamin D.; Zhong, Jian; Park, Jinseong; Chen, Wei; Cui, Yi; Bao, Zhenan

doi:10.1021/nl303410g

Cited by 133 publications

(149 citation statements)

References 81 publications

(127 reference statements)

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“…Vertical 2D heterostructures have also been used to create high-performance Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) (6), tunneling field-effect transistors (FETs) (4), barristors (7), inverters (8), and memory devices (9,10), in addition to facilitating the study of novel physical phenomena in layered materials (11)(12)(13)(14). Similarly, in-plane graphene heterostructures and controlled doping have served as the basis for unique 2D devices (15)(16)(17)(18). Although the nearly perfect 2D structure and low density of states in graphene provide advantages in some heterostructure devices, its gapless nature prevents the formation of a large potential barrier for charge separation and current rectification despite efforts to create in-plane p-n homojunctions by split gating (19).…”

mentioning

confidence: 99%

Gate-tunable carbon nanotube–MoS ₂ heterojunction p-n diode

Jariwala

Sangwan

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

379

344

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The p-n junction diode and field-effect transistor are the two most ubiquitous building blocks of modern electronics and optoelectronics. In recent years, the emergence of reduced dimensionality materials has suggested that these components can be scaled down to atomic thicknesses. Although high-performance fieldeffect devices have been achieved from monolayered materials and their heterostructures, a p-n heterojunction diode derived from ultrathin materials is notably absent and constrains the fabrication of complex electronic and optoelectronic circuits. Here we demonstrate a gate-tunable p-n heterojunction diode using semiconducting single-walled carbon nanotubes (SWCNTs) and single-layer molybdenum disulfide as p-type and n-type semiconductors, respectively. The vertical stacking of these two direct band gap semiconductors forms a heterojunction with electrical characteristics that can be tuned with an applied gate bias to achieve a wide range of charge transport behavior ranging from insulating to rectifying with forward-to-reverse bias current ratios exceeding 10 4 . This heterojunction diode also responds strongly to optical irradiation with an external quantum efficiency of 25% and fast photoresponse <15 μs. Because SWCNTs have a diverse range of electrical properties as a function of chirality and an increasing number of atomically thin 2D nanomaterials are being isolated, the gate-tunable p-n heterojunction concept presented here should be widely generalizable to realize diverse ultrathin, highperformance electronics and optoelectronics.2D transition metal dichalcogenide | single layer MoS 2 | van der Waals heterostructure | rectifier | photodetector

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mentioning

confidence: 99%

Gate-tunable carbon nanotube–MoS ₂ heterojunction p-n diode

Jariwala

Sangwan

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

379

344

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“…However, the continuous and reliable tuning of the threshold voltage of SWNT TFTs has not been achieved, thereby hindering optimal SWNT circuit performance. In addition, although several groups have fabricated flexible (11, 12, 13) SWNT unipolar circuits, the fabrication of SWNT CMOS electronics on a flexible substrate has yet to be reported.We recently described the use of dimethyl-dihydro-benzoimidazoles (DMBI) as a highly efficient class of molecular dopants for [6,6]-phenyl-C 61 -butyric acid methyl ester (PCBM), C 60 , and graphene (33)(34)(35). Because these dopants can be deposited via solution processing, their use can be envisioned in largearea printable electronics.…”

mentioning

confidence: 99%

“…We recently described the use of dimethyl-dihydro-benzoimidazoles (DMBI) as a highly efficient class of molecular dopants for [6,6]-phenyl-C 61 -butyric acid methyl ester (PCBM), C 60 , and graphene (33)(34)(35). Because these dopants can be deposited via solution processing, their use can be envisioned in largearea printable electronics.…”

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confidence: 99%

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Tuning the threshold voltage of carbon nanotube transistors by n-type molecular doping for robust and flexible complementary circuits

Wang

Wei

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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189

174

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Tuning the threshold voltage of a transistor is crucial for realizing robust digital circuits. For silicon transistors, the threshold voltage can be accurately controlled by doping. However, it remains challenging to tune the threshold voltage of single-wall nanotube (SWNT) thin-film transistors. Here, we report a facile method to controllably n-dope SWNTs using 1H-benzoimidazole derivatives processed via either solution coating or vacuum deposition. The threshold voltages of our polythiophene-sorted SWNT thin-film transistors can be tuned accurately and continuously over a wide range. Photoelectron spectroscopy measurements confirmed that the SWNT Fermi level shifted to the conduction band edge with increasing doping concentration. Using this doping approach, we proceeded to fabricate SWNT complementary inverters by inkjet printing of the dopants. We observed an unprecedented noise margin of 28 V at V DD = 80 V (70% of 1/2V DD ) and a gain of 85. Additionally, robust SWNT complementary metal−oxide−semiconductor inverter (noise margin 72% of 1/2V DD ) and logic gates with rail-torail output voltage swing and subnanowatt power consumption were fabricated onto a highly flexible substrate. nanomaterials | n-doping | inkjet-printed | CMOS circuit F lexible electronics have attracted increasing attention recently due to the plethora of possible and realized applications in radio-frequency identification cards (1, 2), flexible displays (3, 4), and digital processors (5). Solution-processed single-walled carbon nanotubes (SWNTs) are a promising candidate for flexible circuits due to their high charge carrier mobility (6), excellent flexibility/stretchability (7-9), and their compatibility with lowcost, large-area manufacturing processes, such as printing (1, 10) of SWNTs. Their applications in thin-film transistors (TFTs) and integrated logic circuits (11-14) have been demonstrated. However, to achieve robust digital circuits with high immunity against the influence of electronic noise in the system, it is important to be able to control the specific value of the threshold voltage of a transistor during the fabrication process (15,16). This is because transistor threshold voltage determines the input voltage at which a circuit switches between two logic states (trip voltage of an inverter). When the trip voltage is half of the supply voltage, the circuit has the largest noise margin, which is a quantitative measure of the immunity of a logic circuit against noise and a figure of merit to characterize the robustness of the circuit (17, 18). If threshold voltage cannot be controlled during the fabrication process, the resulting circuit might not work reliably due to the electrical noise that is always present in the system. Because SWNTs have ambipolar electrical transport properties (19), accurately tuning the threshold voltage permits the construction of complementary metal−oxide−semiconductor (CMOS) circuits that use both the p-type and n-type character of SWNTs. The advantages of CMOS circuits compared with unipolar ...

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“…[12]- [15] However, these reported materials appear to be not versatile from the application point of view, because of the instability of the neutral state in air [16] and the restriction to only some electrode materials to completely cause electron transfer. [14] Therefore, finding a molecular donor, compatible with both vacuum-deposition and solution processes such as drop-casting, is desirable to be incorporated as a WF-reducer for bottom and top electrodes into all-solution processed or multilayer devices. [17]- [18] The dimers formed by some 19-electron organometallic sandwich compounds, such as the dimer of 1,2,3,4,5-pentamethylrhodocene (1 2 , molecular structure shown in Figure 1), are promising candidates for this purpose: their reductant ability has already been demonstrated by the effective n-doping for a variety of organic semiconductors, [19] their 18-electron configurations lead to moderate air-stability, and they can be processed using both vacuum deposition at low temperature (~120 ºC) and solution processes.…”

Section: Introductionmentioning

confidence: 99%

Effective Work Function Reduction of Practical Electrodes Using an Organometallic Dimer

Akaike

Nardi

Oehzelt

et al. 2016

Adv Funct Materials

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The control of the cathode work function (WF) is essential to enable efficient electron injection and extraction at organic semiconductor/cathode interfaces in organic electronic devices. The adsorption of an air-stable molecular donor onto electrodes, compatible with both evaporation and solution processes, is a simple way to reduce the WF. Such a versatile molecule, however, has not been identified yet. In this paper, ultraviolet photoelectron spectroscopy is used to confirm that depositing an ultrathin layer of the moderately air-stable pentamethylrhodocene-dimer onto various conducting electrodes, by either vacuum 2 deposition or drop-casting from solution, substantially reduces their WF to less than 3.6 eV, with 2.8 eV being the lowest attainable value. Detailed measurements of the Rh core levels with X-ray photoelectron spectroscopy reveal that the electron transfer from the molecule to the respective substrates is responsible for the appreciable WF reduction. Notably, even after air-exposure, the WF of the donor-covered electrodes remains below those of typically used clean cathode-metals such as Al and Ag, rendering the approach appealing for practical applications. The WF reduction, together with the observed air-stability of the covered electrodes, demonstrates the applicability of the pentamethylrhodocene-dimer to reduce the WF for a wide range of electrodes used in all-organic or organic-inorganic hybrid devices.

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Tuning the Dirac Point in CVD-Grown Graphene through Solution Processed n-Type Doping with 2-(2-Methoxyphenyl)-1,3-dimethyl-2,3-dihydro-1H-benzoimidazole

Cited by 133 publications

References 81 publications

Gate-tunable carbon nanotube–MoS ₂ heterojunction p-n diode

Gate-tunable carbon nanotube–MoS ₂ heterojunction p-n diode

Tuning the threshold voltage of carbon nanotube transistors by n-type molecular doping for robust and flexible complementary circuits

Effective Work Function Reduction of Practical Electrodes Using an Organometallic Dimer

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Tuning the Dirac Point in CVD-Grown Graphene through Solution Processed n-Type Doping with 2-(2-Methoxyphenyl)-1,3-dimethyl-2,3-dihydro-1H-benzoimidazole

Cited by 133 publications

References 81 publications

Gate-tunable carbon nanotube–MoS 2 heterojunction p-n diode

Gate-tunable carbon nanotube–MoS 2 heterojunction p-n diode

Tuning the threshold voltage of carbon nanotube transistors by n-type molecular doping for robust and flexible complementary circuits

Effective Work Function Reduction of Practical Electrodes Using an Organometallic Dimer

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Product

Resources

About

Gate-tunable carbon nanotube–MoS ₂ heterojunction p-n diode

Gate-tunable carbon nanotube–MoS ₂ heterojunction p-n diode