Banca de DEFESA: JAYANE OLIVEIRA BORGES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE: JAYANE OLIVEIRA BORGES
DATA: 15/02/2024
HORA: 09:00
LOCAL: Presencial - Auditório do Departamento de Fisica/UFPI
TÍTULO: FILMES FINOS DE ÓXIDO DE ALUMÍNIO OBTIDOS POR DIFERENTES TÉCNICAS PARA APLICAÇÕES EM DISPOSITIVOS OPTOELETRÔNICOS.
PALAVRAS-CHAVES: filmes finos, óxido de alumínio, anodização, dispositivos, memória.
PÁGINAS: 80
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
RESUMO:

The objective of this work is to characterize the aluminum oxide obtained by the
anodizing technique of aluminum using a solution of 0.4 M phosphoric acid diluted in
Milli-Q water. Anodizing generates a thickening of the oxide layer present on the
surface of the aluminum, it occurs due to the passage of electric current when the metal
is submerged in an appropriate aqueous solution. In the anodizing experiment the metal
is bonded to the positive pole of a voltage source, acting as the anode in the electrolytic
cell, an inert counter electrode (platinum or gold) to the chemical solution is adopted as
a cathode in the experiment, being connected to the negative pole of the voltage source.
This type of process can be carried out by two methods, one of them applying a constant
current, and the second corresponding to the application of a constant voltage. In the
present work, different values of tension and time were applied during the anodizing
process. For the characterization of the thin aluminum oxide films, UV-VIS
spectroscopy measurements were performed, which proved the increase in the
transmittance of the film with the thickening of the oxide layer, in addition to revealing
the relationship of voltage and time with the growth of the film. The samples were also
analyzed by the Fourier Transform Infrared (FTIR) technique, where the ATR (total

Este formulário deve ser preenchido eletronicamente e enviado com pelo 25 dias de
antecedência à defesa para a secretaria do programa pelo e-mail eugenia@ufpi.edu.br.
Atualizado em 21/03/2018
attenuated reflectance) method was used to evaluate the molecular structure of the
oxide, it was verified through this technique that the Al presents a band only around 950
cm -1 in addition to the contribution of 730 cm -1 which intensifies depending on the
anodizing conditions as well as the shape of the main band. Raman measurements
revealed the amorphous character of the anodized oxides, and another comparison was
made with temperature-treated samples that tended to be more crystalline. Electrical
characterizations were carried out using the 4-point technique, which proved the growth
of the material's resistance with the anodizing treatment. In addition, a device was built
to perform exploratory I-V (current-voltage) measurements, where memory effects were
observed with the structure adopted for the construction of the device. The anodized
samples underwent a morphological characterization through the AFM technique where
the roughness and fractal dimension were analyzed. The main focus of this study is to
explore the application of this aluminum oxide layer in organic electronic devices.
Through the detailed characterization of the properties of aluminum oxide, we seek to
understand its potential to improve the performance and stability of these devices. The
results obtained in these measurements will provide valuable information for the
development of future practical applications of organic electronic devices using
aluminum oxide as a functional layer.

MEMBROS DA BANCA:
Externo ao Programa - 2065436 - ALEXANDRE DE CASTRO MACIEL
Externo à Instituição - AYRTON DE SÁ BRANDIM - IFPI
Interno - 1720015 - GARDENIA DE SOUSA PINHEIRO
Externo ao Programa - 423287 - JOSE RIBEIRO DOS SANTOS JUNIOR
Presidente - 1714296 - MARIA LETICIA VEGA