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Abstract As known, n‐type inorganic semiconductor nanoparticles such as zinc oxide nanoparticles have been explored in various sensing applications, which demand high‐density electronic elements placement for rapid operation. Herein, high‐resolution designs of conductive channels of noble metal‐doped zinc oxide nanoparticles is demonstrated using an engraving transfer printing process and silver metal doping approach. Such thin‐film transistors with reduced feature size to 2 µm fabricated exhibited significantly enhanced electron mobility up 3.46 × 10−2cm2V−1s−1and light sensitivity. Furthermore, the integration of this micropatterning technology and metal doping in thin‐film transistors is utilized for control of current–voltage characteristics under the ultraviolet radiation with high sensitivity. It is suggested that this approach to design of doped inorganic nanoparticle channels paves the way for high‐density thin‐film transistors suitable for optoelectronic circuit, UV photodetectors and neuromorphic computing systems.
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The role of third cation doping on phase stability, carrier transport and carrier suppression in amorphous oxide semiconductors
Amorphous oxide semiconductors (AOSs), specifically those based on ternary cation systems such as Ga-, Si-, and Hf-doped InZnO, have emerged as promising material candidates for application in next-gen transparent electronic and optoelectronic devices. Third cation-doping is a common method used during the manufacturing of amorphous oxide thin film transistors (TFTs), primarily with the intention of suppressing carrier generation during the fabrication of the channel layer of a transistor. However, the incorporation of a third cation species has been observed to negatively affect the carrier transport properties of the thin film, as it may act as an additional scattering center and subsequently lower the carrier mobility from ∼20–40 cm 2 V −1 s −1 of In 2 O 3 or a binary cation system ( i.e. , InZnO) to ∼1–10 cm 2 V −1 s −1 . This study investigates the structural, electrical, optoelectronic, and chemical properties of the ternary cation material system, InAlZnO (IAZO). The optimized carrier mobility (Hall Effect) of Al-doped InZnO is shown to remain as high as ∼25–45 cm 2 V −1 s −1 . Furthermore, Al incorporation in InZnO proves to enhance the amorphous phase stability under thermal stresses when compared to baseline InZnO films. Thin film transistors integrating optimized IAZO as the channel layer are shown to demonstrate promisingly high field effect mobilities (∼18–20 cm 2 V −1 s −1 ), as well as excellent drain current saturation and high drain current on/off ratios (>10 7 ). The high mobility and improved amorphous phase stability suggest strong potential for IAZO incorporation in the next generation of high performance and sustainable optoelectronic devices such as transparent displays.
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- Award ID(s):
- 1931088
- PAR ID:
- 10289742
- Date Published:
- Journal Name:
- Journal of Materials Chemistry C
- Volume:
- 8
- Issue:
- 39
- ISSN:
- 2050-7526
- Page Range / eLocation ID:
- 13798 to 13810
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract New deposition techniques for amorphous oxide semiconductors compatible with silicon back end of line manufacturing are needed for 3D monolithic integration of thin‐film electronics. Here, three atomic layer deposition (ALD) processes are compared for the fabrication of amorphous zinc tin oxide (ZTO) channels in bottom‐gate, top‐contact n‐channel transistors. As‐deposited ZTO films, made by ALD at 150–200 °C, exhibit semiconducting, enhancement‐mode behavior with electron mobility as high as 13 cm2V−1s−1, due to a low density of oxygen‐related defects. ZTO deposited at 200 °C using a hybrid thermal‐plasma ALD process with an optimal tin composition of 21%, post‐annealed at 400 °C, shows excellent performance with a record high mobility of 22.1 cm2V–1s–1and a subthreshold slope of 0.29 V dec–1. Increasing the deposition temperature and performing post‐deposition anneals at 300–500 °C lead to an increased density of the X‐ray amorphous ZTO film, improving its electrical properties. By optimizing the ZTO active layer thickness and using a high‐kgate insulator (ALD Al2O3), the transistor switching voltage is lowered, enabling electrical compatibility with silicon integrated circuits. This work opens the possibility of monolithic integration of ALD ZTO‐based thin‐film electronics with silicon integrated circuits or onto large‐area flexible substrates.more » « less
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/D0TC02655G
