Use of underpotential deposition in the dopping of electrodeposited selenium semiconductive films.

• Grant number: 11/07022-4
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: August 01, 2011
• End date: January 31, 2015
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Sergio Antonio Spinola Machado
• Grantee: Dyovani Coelho
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

In this project we will study the effects of the doping of selenium films with ad-atoms Bi, Pb and Cu in the semiconducting properties of these films. The selenium films will be obtained by chronoamperometry into electrolytes containing SeO2 and different acids. These films will be deposited on polycrystalline gold (or quartz covered with polycrystalline gold, when studying at microbalance electrode electrochemical quartz crystal). The conditions of concentration, temperature and deposition time will be evaluated in order to obtain films of higher possible homogeneity and crystallinity. These films will be characterized by cyclic voltammetry (coverage and characterization of voltammetric profile), atomic force microscopy and scanning electron microscopy (morphology), electrochemical microbalance quartz crystal (mass variations), X-ray diffraction (amorphous or crystalline feature and identification of phases), electrochemical impedance spectroscopy (flat band potential, type of semiconductor and donor or acceptor density) and absorption in the ultraviolet-visible or diffuse reflectance spectroscopy (band gap). After, Bi, Pb and Cu ad-atoms will be underpotential deposited on the selenium films. The amount of ad-atoms and the effects on film properties will be evaluated. For this purpose, cyclic voltammetry will be used to investigate the potential range where occurs the underpotential deposition of the metals on the selenium film. After the depositions, the films will be again characterized in order to determine the influence of ad-atoms on their properties using the techniques described above.

Scientific publications

(4)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CABRAL, MURILO F.; COELHO, DYOVANI; MACHADO, SERGIO A. S.. Analyzing Cd underpotential deposition behavior on Se thin-films: Atomic force microscopy, cyclic voltammetry and electrochemical quartz crystal nanobalance studies. Electrochimica Acta, v. 91, p. 361-366, FEB 28 2013. (11/07022-4, 10/09795-8)

DYOVANI COELHO; GIULIANA M. LUIZ; SERGIO A. S. MACHADO. Estimating the Electrochemically Active Area: Revisiting a Basic Concept in Electrochemistry. Journal of the Brazilian Chemical Society, v. 32, n. 10, p. 1912-1917, 2021-10-01. (13/17053-0, 11/07022-4)

COELHO, DYOVANI; LUIZ, GIULIANO M.; MACHADO, SERGIO A. S.. A photoelectrochemical methodology to obtain nanorods of crystalline hexagonal trigonal selenium. JOURNAL OF ELECTROANALYTICAL CHEMISTRY, v. 820, p. 89-96, JUL 1 2018. (13/17053-0, 11/07022-4)

COELHO, DYOVANI; MACHADO, SERGIO A. S.. New contribution in the study of phase formation in mixed alkanethiol self-assembled monolayers: a powerful tool for transducers design. Electrochimica Acta, v. 142, p. 191-201, OCT 1 2014. (13/17053-0, 11/07022-4, 10/03813-4)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

COELHO, Dyovani. Use of underpotential deposition in the doping of electrodeposited selenium semiconductive films. 2015. Doctoral Thesis - Universidade de São Paulo (USP). Instituto de Química de São Carlos (IQSC/BT) São Carlos.