Optimization of the Electrical Performance of Metal Oxide Thin-film Transistors by varying Spray Deposition Parameters

Autor(es)

de Lima, Guilherme R. ^[1] ; Braga, Joao Paulo ^[1] ; Gozzi, Giovani ^[2] ; Santos, Lucas Fugikawa ^{[1, 2]}

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista UNESP, Dept Fis, Rua Cristovao Colombo 2265, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

^[2] Univ Estadual Paulista UNESP, Dept Fis, Ave 24 A, 1515, BR-13500970 Rio Claro, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MRS ADVANCES; v. 3, n. 5, p. 247-253, 2018.
• Citações Web of Science: 0

Resumo

Metal oxides like zinc oxide (ZnO) are promising materials for the active layer of thin-film transistors (TFTs) used in the drive circuit of next-generation large-area active matrix displays due to their high electronic mobility, high transmittance in the optical visible range and processability. Traditional deposition techniques employ RF sputtering or pulsed-laser deposition (PLD), which are relatively sophisticated techniques. The deposition of very thin (less than 50 nm thick) layers of ZnO using soluble organic precursors have been extensively investigated recently as an alternative to traditional deposition methods. Solution-based deposition processes include simple and affordable techniques like dip-coating, spin-coating, spray-pyrolysis and ink-jet printing. Spray-pyrolysis is particularly interesting due to the high film uniformity, low cost and high device performance. We carried out several experiments analyzing the performance of ZnO based devices using zinc acetate as organic precursor to confirm that spray pyrolysis deposition is a suitable technique for production of high-performance and reproducible TFTs. Moreover, we observed that device performance can significantly vary with little modifications on the deposition parameters, even for the same active layer composition and pyrolysis temperature. Electrical parameters, as the electrical mobility and the on/off ratio, varied several orders of magnitude, whereas the threshold voltage varied up to 20 V for the tested devices. Deposition parameters as the nozzle height during the deposition, nozzle air pressure and deposition time were varied until we obtained devices with optimum electrical performance. Optimized devices presented mobilities in the order of 1 cm(2).V-1.s(-1), on/off ratio of about 106 and relatively low operation voltages. A statistical analysis of a great number of devices manufactured using the same deposition parameters was also carried out to assure the reproducibility of the deposition technique. (AU)

• Processo FAPESP: 13/24461-7 - Estudo da influência do controle de atmosfera no desempenho de transistores de filme fino para aplicações em circuitos transparentes e/ou flexíveis
• Beneficiário: Lucas Fugikawa Santos
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 08/57706-4 - Instituto Nacional de Eletrônica Orgânica (INEO)
• Beneficiário: Roberto Mendonça Faria
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 17/22018-0 - 2017 MRS Fall Meeting and Exhibit
• Beneficiário: Lucas Fugikawa Santos
• Modalidade de apoio: Auxílio à Pesquisa - Reunião - Exterior