Customizing the Polarity of Single‐Walled Carbon‐Nanotube Field‐Effect Transistors Using Solution‐Based Additives

Abstract

Polarity control in semiconducting single‐walled carbon‐nanotube field‐effect transistors (s‐SWNT FETs) is important to promote their application in logic devices. The methods to turn the intrinsically ambipolar s‐SWNT FETs into unipolar devices that have been proposed until now require extra fabrication steps that make preparation longer and more complex. It is demonstrated that by starting from a highly purified ink of semiconducting single‐walled carbon nanotubes sorted by a conjugated polymer, and mixing them with additives, it is possible to achieve unipolar charge transport. The three additives used are benzyl viologen (BV), 4‐(2,3‐dihydro‐1,3‐dimethyl‐1H‐benzimidazol‐2‐yl)‐N,N‐dimethylbenzenamine (N‐DMBI), which give rise to n‐type field‐effect transistors, and 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane (F4‐TCNQ) which gives rise to p‐type transistors. BV and N‐DMBI transform the s‐SWNTs transistors from ambipolar with mobility of the order of 0.7 cm2 V−1 s−1 to n‐type with mobility up to 5 cm2 V−1 s−1. F4‐TCNQ transform the ambipolar transistors in p‐type with mobility up to 16 cm2 V−1 s−1.

Toward Unusual‐High Hole Mobility of p‐Channel Field‐Effect‐Transistors

“…Beyond the effective control of V TH and SS, the hole mobility of GaSb NWFETs is also manipulated well by metal-semiconductor junctions, as shown in Figure 2f and Figure S3g-i, Supporting Information. Similar to the case of Al deposition, the peak hole mobility of GaSb NWFETs increases to 1938 and [23,24] SnO, [25][26][27][28] WS 2 , [29,30] CNT, [31][32][33] NiO, [34] Te, [35] MoTe 2 , [36][37][38] MoS 2 , [39,40] GeAs, [41] WSe 2 , [42,43] Ge, [44][45][46] InSb, [47] BP, [48][49][50][51] GaSb [16,[21][22][52][53][54] ) FETs in the literatures (at room temperature in the atmosphere).…”

“…a) Typical atomic force microscopy (AFM) image of GaSb NWFET deposited with 0.5 nm Al film. Inset shows the corresponding three-dimensional AFM image of channel GaSb NW; b) transfer characteristics of GaSb NWFET before and after the deposition of Al film; c) V TH shift statistics of GaSb NWFETs deposited with different thicknesses of Al films (V DS = 0.1 V);d) field-effect (FE) mobility of GaSb NWFET before and after depositing 0.5 nm Al film; e) statistics of mobility enhancement of GaSb NWFETs as function of Al film thickness (V DS = 0.1 V); f) FE hole mobilities of typical p-channel (CuO,[23,24] SnO,[25][26][27][28] WS 2 ,[29,30] CNT,[31][32][33] NiO,[34] Te,[35] MoTe 2 ,[36][37][38] MoS 2 ,[39,40] GeAs,[41] WSe 2 ,[42,43] Ge,[44][45][46] InSb,[47] BP,[48][49][50][51] GaSb[16,[21][22][52][53][54] ) FETs in the literatures (at room temperature in the atmosphere).…”

Synaptic Plasticity in Semiconducting Single‐Walled Carbon Nanotubes Transistors

“…The use of a different dielectric can bring the bias to only a few volts and to a variation of the hysteresis. [35,36] Additional characterization data are found in Figure S1, Supporting Information.…”

Recent progress in the development of backplane thin film transistors for information displays

“…Additives to a CNT solution, or a doping layer atop the CNT layer, can increase the charge-carrier density of the active layer. For example, the hole current can be slightly increased by the strong electron affinity of tetrafluorotetracyano-p-quinodimethane (F4TCNQ), p-dopant [71,72]. In contrast, electron density can be increased by application of n-dopants such as Polyethylenimine (PEI) [73,74] and dimethyl-dihydrobenzoimidazoles (DMBI) [72,75].…”