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Bukke RN, Saha JK, Mude NN, Kim Y, Lee S, Jang J. Lanthanum Doping in Zinc Oxide for Highly Reliable Thin-Film Transistors on Flexible Substrates by Spray Pyrolysis. ACS Appl Mater Interfaces 2020; 12:35164-35174. [PMID: 32657115 DOI: 10.1021/acsami.0c05151] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Solution-processed metal-oxide thin-film transistors (TFTs) are considered as one of the most favorable devices for next-generation, large-area flexible electronics. In this paper, we demonstrate the excellent material properties of lanthanum-zinc oxide (LaZnO) thin films deposited by spray pyrolysis and their application to TFTs. The threshold voltage of the LaZnO TFTs shifts toward positive gate voltage, and the mobility decreases with increasing lanthanum ratio in ZnO from 0 to 20%. The purification of the LaZnO precursor (P-LaZnO) further improves the device performance. The P-LaZnO TFT exhibits a field-effect mobility of 22.43 cm2 V-1 s-1, zero hysteresis voltage, and negligible threshold voltage VTH shift under positive bias temperature stress. The enhancement in the electrical properties is due to a decrease in grain size, smooth surface roughness, and reduction in the trap density in the LaZnO film. X-ray photoelectron spectroscopy (XPS) results confirm the presence of La in the TFT channel and at/near the interface of the LaZnO and ZrOx gate insulator, leading to fewer interfacial traps. The flexible P-LaZnO TFT fabricated on the polyimide substrate exhibits a mobility of 17.64 cm2 V-1 s-1 and a negligible VTH shift under bias stress. Also, the inverter made of LZO TFTs is working well with a voltage gain of 17.74 (V/V) at 4 V. Therefore, the LaZnO TFT is a promising device for next-generation flexible displays.
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Affiliation(s)
- Ravindra Naik Bukke
- Advanced Display Research Center (ADRC), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
| | - Jewel Kumer Saha
- Advanced Display Research Center (ADRC), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
| | - Narendra Naik Mude
- Advanced Display Research Center (ADRC), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
| | - Youngoo Kim
- Advanced Display Research Center (ADRC), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
| | - Suhui Lee
- Advanced Display Research Center (ADRC), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
| | - Jin Jang
- Advanced Display Research Center (ADRC), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
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Park JW, Tak YJ, Na JW, Lee H, Kim WG, Kim HJ. Effect of Static and Rotating Magnetic Fields on Low-Temperature Fabrication of InGaZnO Thin-Film Transistors. ACS Appl Mater Interfaces 2018; 10:16613-16622. [PMID: 29682960 DOI: 10.1021/acsami.8b02433] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We suggest thermal treatment with static magnetic fields (SMFs) or rotating magnetic fields (RMFs) as a new technique for the activation of indium-gallium-zinc oxide thin-film transistors (IGZO TFTs). Magnetic interactions between metal atoms in IGZO films and oxygen atoms in air by SMFs or RMFs can be expected to enhance metal-oxide (M-O) bonds, even at low temperature (150 °C), through attraction of metal and oxygen atoms having their magnetic moments aligned in the same direction. Compared to IGZO TFTs with only thermal treatment at 300 °C, IGZO TFTs under an RMF (1150 rpm) at 150 °C show superior or comparable characteristics: field-effect mobility of 12.68 cm2 V-1 s-1, subthreshold swing of 0.37 V dec-1, and on/off ratio of 1.86 × 108. Although IGZO TFTs under an SMF (0 rpm) can be activated at 150 °C, the electrical performance is further improved in IGZO TFTs under an RMF (1150 rpm). These improvements of IGZO TFTs under an RMF (1150 rpm) are induced by increases in the number of M-O bonds due to enhancement of the magnetic interaction per unit time as the rpm value increases. We suggest that this new process of activating IGZO TFTs at low temperature widens the choice of substrates in flexible or transparent devices.
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Affiliation(s)
- Jeong Woo Park
- School of Electrical and Electronic Engineering , Yonsei University , 50 Yonsei-ro , Seodaemun-gu, Seoul 03722 , Republic of Korea
| | - Young Jun Tak
- School of Electrical and Electronic Engineering , Yonsei University , 50 Yonsei-ro , Seodaemun-gu, Seoul 03722 , Republic of Korea
| | - Jae Won Na
- School of Electrical and Electronic Engineering , Yonsei University , 50 Yonsei-ro , Seodaemun-gu, Seoul 03722 , Republic of Korea
| | - Heesoo Lee
- School of Electrical and Electronic Engineering , Yonsei University , 50 Yonsei-ro , Seodaemun-gu, Seoul 03722 , Republic of Korea
| | - Won-Gi Kim
- School of Electrical and Electronic Engineering , Yonsei University , 50 Yonsei-ro , Seodaemun-gu, Seoul 03722 , Republic of Korea
| | - Hyun Jae Kim
- School of Electrical and Electronic Engineering , Yonsei University , 50 Yonsei-ro , Seodaemun-gu, Seoul 03722 , Republic of Korea
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