Direct Synthesis of Semiconducting Single‐Walled Carbon Nanotubes Toward High‐Performance Electronics

Abstract

The large‐scale synthesis of high‐purity semiconducting single‐walled carbon nanotubes (s‐SWCNTs) plays a crucial role in fabricating high‐performance and multiapplication‐scenario electronics. This work develops a straightforward, continuous, and scalable method to synthesize high‐purity and individual s‐SWCNTs with small‐diameters distribution (≈1 nm). It is believed that the water and carbon dioxide resulting from the decomposition of isopropanol act as oxidizing agents and selectively etch metallic SWCNTs, hence enhancing the production of s‐SWCNTs. The performance of individual‐SWCNTs field effect transistors confirms the high abundance of s‐SWCNTs, presenting a mean mobility of 376 cm2 V−1 s−1 and a high mobility of 2725 cm2 V−1 s−1 with an on‐current to off‐current (Ion/Ioff) ratio as high as 2.51 × 107. Moreover, thin‐film transistors based on the as‐synthesized SWCNTs exhibit excellent performance with a mean mobility of 9.3 cm2 V−1 s−1 and Ion/Ioff ratio of 1.3× 105, respectively, verifying the enrichment of s‐SWCNTs. This work presents a simple and feasible route for the sustainable synthesis of high‐quality s‐SWCNTs for electronic devices.

Wafer-Scale Fabrication of Wearable All-Carbon Nanotube Photodetector Arrays

“…Specifically, the purity of s-SWCNTs in this work is about 94%, calculated using the method reported in our previous work. 7 This observation is supported by the Raman spectrum (Figure 2e), where two strong peaks representing the s-SWCNTs appear in the Raman shift above 200 cm −1 . Excitingly, the channel material exhibits an impressive On/Off ratio exceeding 10 5 within a gate voltage range of −10 to +10 V, indicating its p-type semiconductor characteristics (Figure 2f).…”

“…The CNTs are directly deposited on the membrane filter by gas flow to form various patterns, and the CNT thickness can be precisely controlled through collection time. 7 Figure 1b shows the diversity of custom patterns such as crossed electrodes, logos, electrode pairs, metasurface, and animal patterns. The third step is to transfer the patterned CNT film to the target substrate via dry pressing.…”

“…The electrode and channel materials of wearable devices are composed of CNTs synthesized through the FCCVD method. 7,25 using a double Cs-corrected transmission electron microscope (TEM). A typical TEM image of the CNT is displayed in the inset of Figure 2a, revealing a distinct double-walled structure with a tube diameter of about 4 nm.…”

“…26 To understand the transfer properties of CNTs, bottom-gate transistors were fabricated using Ti/Pd as electrodes and as-synthesized CNTs as the channel materials. 7 Figure 2c presents the transfer curve of the CNT electrode material under a bias of −50 mV and gate voltage ranges of −10 to +10 V, and the flat curve indicates that the electrode material is metallic and can be selected as a conductive electrode for flexible devices. Additionally, through atomic force microscope (AFM) testing, it was determined that the thickness of the DWCNT electrode is approximately 40 nm (Figure S3).…”

“…Comprehensive details on the synthesis process of SWCNTs can be found in our earlier report. 7 Subsequently, as-synthesized SWCNTs were deposited on the top of patterned DWCNT electrode arrays using the direct thermophoretic method. 24 Fabrication of CNT transistors.…”