Banca de DEFESA: GUSTAVO GOMES VASQUES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : GUSTAVO GOMES VASQUES
DATA : 15/04/2021
HORA: 10:00
LOCAL: Online
TÍTULO:

Electrical characterization of Fullerene C60 devices

PÁGINAS: 60
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
SUBÁREA: Física da Matéria Condensada
ESPECIALIDADE: Estados Eletrônicos
RESUMO:

Organic materials have been attracting attention due to the low-cost, flexibility and possibility of covering large areas with thin films. Fullerene C60 is a well-known n-type material with high electrical conductivity in its crystalline phase, but this can be changed in thin films. The aim of this work is to elucidate the dependence on sample thickness of the electrical properties of Fullerene C60 thin films, to help build devices using this material as an n-type active layer. We report on the development of devices based on Fullerene C60 thin films, vapor-deposited in vacuum between indium tin oxide (ITO) substrate and aluminum contacts. Four thicknesses of the C60 layer were investigated (50 nm, 100 nm, 150 nm and 220 nm). Initial characterizations were conducted by measurements of I x V curves, where thicker films present diode behavior, and thinner samples show increase in the number of traps and decrease in the limit of the applied voltage (50 nm and 100 nm layer deteriorate at 7 V). Further characterization involved impedance spectroscopy, where measurements of C x V; C x frequency and conductance x frequency were done. An inversion zone and the formation of a peak related with Maxwell-Wagner relaxation of the dielectric is observed. Since organic devices tend to present noisy response, data analysis requires extra attention, and despite C60 being a stable molecule we find that within 4 days the properties of the devices change. 

MEMBROS DA BANCA:
Membro Titular - Examinador(a) Externo ao Programa - 1762413 - LUCIANO SOARES DA CRUZ
Membro Titular - Examinador(a) Externo à Instituição - JOSÉ PEDRO MANSUETO SERBENA
Presidente - Externo ao Programa - 1676378 - ADRIANO REINALDO VICOTO BENVENHO
Membro Suplente - Examinador(a) Interno ao Programa - 1671599 - MARCOS DE ABREU AVILA
Membro Suplente - Examinador(a) Externo ao Programa - 2604737 - EVERALDO CARLOS VENANCIO