Banca de QUALIFICAÇÃO: GABRIEL HENRIQUE INÁCIO DE OLIVEIRA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : GABRIEL HENRIQUE INÁCIO DE OLIVEIRA
DATA : 16/08/2022
HORA: 13:00
LOCAL: Sala 302A do Bloco B do Campus Santo André da Universidade Federal do ABC
TÍTULO:

ATTAINMENT OF TRANSPARENT CONDUCTIVE OXIDE OF ALUMINUM-DOPED ZINC OXIDE (AZO)

PÁGINAS: 97
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Elétrica
SUBÁREA: Materiais Elétricos
ESPECIALIDADE: Materiais e Componentes Semicondutores
RESUMO:

The study presented in this master's program aims to obtain transparent aluminum-doped zinc oxide (AZO) films for application as a transparent conductive oxide (TCO) film. AZO films have been studied to replace ITO and FTO films used as electrodes in solar cells. ITO and FTO films have disadvantages such as high production cost (due to the price of indium), rarity, instability in hydrogen plasma [1] and are considered toxic elements [2]. AZO has its advantages compared to ITO and FTO such as low toxicity, high abundance of zinc in nature and cheaper than indium and fluorine [3]. The thin film deposition technique used in this work was the R.F. Magnetron Sputtering. A zinc target was used and doping was performed using aluminum wires on the target, allowing to control the composition of the deposited film. The AZO film was obtained from the oxidation of the aluminum-doped zinc film. This technique has the advantage of being compatible with the microelectronics industry, cheap and versatile, as it allows controlling the composition without preparing a target with a fixed composition. Tests were performed with different deposition parameters such as deposition pressure, target-substrate distance and R.F. power to get a Zn film with good deposition rate and low porosity. The deposited AZO films were analyzed and discussed by the following techniques: profilometry to obtain information on thickness and roughness; scanning electron microscopy (SEM) to observe morphology and composition; UV-Vis spectrophotometry to study the optical gap and transmittance; X-ray diffraction (XRD) to analyze the crystallinity and grain size and the four-probe to analyze the resistivity of the films. Preliminary results showed the influence of deposition parameters as RF power and target-sample distance, showing the best results for the 300W power with a distance of 10 cm. The influence of the length of the Al wires used during the deposition was related to the resistivity and transparency of the films. As a result, it was observed that the resistivity decreases with the increase of Al wires, but the films with lower resistivity have low transmittance. In conclusion, it was observed that there is a range of Al wire lengths that results in acceptable resistivity and transmittance values for applications in solar cells. This Al length range will be explored in more detail until the completion of this master's degree.

[1] M. A. M. S. Morteza Shakeri Shamsi, “Al Doped ZnO Thin Films; Preparation and Characterization,” J Nanostruct 8, pp. 404-407, 2018.

[2] X. D. P. D. Tao Wang, “Thermal stability of electrical properties of ZnO:Al films deposited by room temperature Magnetron Sputtering,” Journal of Alloys and Compounds ELSEVIER 509, pp. 4910-4915, 2011.

[3] F. W. J. W. C. K. H. L. H.P. Chang, “Enhanced conductivity of aluminum doped ZnO films by hydrogen plasma treatment,” Thin Solid Films 518, p. 7445–7449 , 2010.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1768304 - DENISE CRIADO PEREIRA DE SOUZA
Membro Titular - Examinador(a) Interno ao Programa - 1671297 - MICHEL OLIVEIRA DA SILVA DANTAS
Membro Titular - Examinador(a) Externo ao Programa - 1838179 - KATIA FRANKLIN ALBERTIN TORRES
Membro Suplente - Examinador(a) Interno ao Programa - 1545447 - MARCOS ROBERTO DA ROCHA GESUALDI
Membro Suplente - Examinador(a) Externo ao Programa - 1986755 - DANIEL SCODELER RAIMUNDO