Tuning positive and negative photoconductivity in Zn1-xCdxO films

Autor(es)

Vargas, Luis M. B. ^[1] ; de Castro, Suelen ^[2] ; Peres, Marcelos L. ^[1] ; de Godoy, Marcio P. F. ^[2] ; Soares, Demetrio A. W. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Itajuba, Inst Fis & Quim, BR-37500903 Itajuba, MG - Brazil

^[2] Univ Fed Sao Carlos, Dept Fis, BR-13565905 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Alloys and Compounds; v. 749, p. 734-740, JUN 15 2018.
• Citações Web of Science: 4

Resumo

Photoconductivity investigation is performed on Zn1-xCdxO films and a transition from positive to negative photoconductivity is observed at room temperature as Cd concentration x is varied. Low and high Cd-content samples are studied by temperature dependent photoconductivity measurements in the temperature range of 77-300 K. Our results exhibited additional transitions manifested by an anomalous persistent effect on sample with x similar to 0.25 and a transition from negative to positive photoconductivity for sample with x similar to 0.75 as temperature changes. The observed negative photoconductivity effect is attributed to trap levels while the anomalous behavior of persistent photoconductivity amplitude is caused by random local potential fluctuations, responsible to spatial separation of electrons and holes at high temperatures. This interpretation is further supported by photoluminescence and electrical resistance measurements. (C) 2018 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 16/10973-4 - Defeitos e suas funcionalidades em filmes óxidos semicondutores obtidos por spray-pirólise
• Beneficiário: Marcio Peron Franco de Godoy
• Modalidade de apoio: Auxílio à Pesquisa - Regular