A photoelectrochemical methodology to obtain nanorods of crystalline hexagonal trigonal selenium

Autor(es)

Coelho, Dyovani ^{[1, 2]} ; Luiz, Giuliano M. ^[2] ; Machado, Sergio A. S. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Sao Carlos Inst Chem, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF ELECTROANALYTICAL CHEMISTRY; v. 820, p. 89-96, JUL 1 2018.
• Citações Web of Science: 0

Resumo

The conditions for trigonal selenium film deposition on gold substrate (f-Se) was investigated using cyclic voltammetry, chronoamperometry, optical microscopy, scanning electron microscopy and X-ray diffraction, which showed the production of a highly crystalline and homogeneous film formed of hexagonal microrods structures with diameters between 300 and 600 nm. However, the film with such characteristics was formed only by deposition into 0.1 mol L-1 HNO3 at 80 degrees C containing 0.02 mol L-1 SeO2 with potential deposition of -0,45 V vs SCE, under illumination with halogen lamp 100 W, irradiance of 200 mW cm(-2), magnetic stirring and deposition time of 600 s or higher. It believed that the mechanism of t-selenium growth is associated with a (photo)electrocorrosion process, where the combination between the incident light and applied potential cause the dissolution of amorphous selenium and favoring the growth of the crystalline faces making them more conductive with the light absorption. The optical characterization of the films determined a band gap of 1.74 +/- 0.03 eV, photoelectrochemical activity, flat band potential of 0.63 +/- 0.17 V vs SCE and charge carriers density of 4.97 +/- 0.90 x 10(15)cm(-3). (AU)

• Processo FAPESP: 13/17053-0 - Desenvolvimento de uma metodologia eletroquímica de dopagem seletiva de filmes semicondutores eletrodepositados de selênio baseado na eletrodeposição em regime de subtensão
• Beneficiário: Sergio Antonio Spinola Machado
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/07022-4 - Utilização da eletrodeposição em regime de subtensão na dopagem de filmes semicondutores eletrodepositados de selênio
• Beneficiário: Dyovani Coelho
• Modalidade de apoio: Bolsas no Brasil - Doutorado