Insights into the nature of optically active defects of ZnO

Author(s)

Cabral, L. ; Lopez-Richard, Victor ; Da Silva, Juarez L. F. ; Marques, G. E. ; Lima, Matheus P. ; Onofre, Y. J. ; Teodoro, M. D. ; de Godoy, M. P. F.

• Document type: Journal article
• Source: Journal of Luminescence; v. 227, p. 10-pg., 2020-11-01.

Abstract

ZnO is a wide bandgap semiconductor in which point and extended defects tune its optoelectronic properties, and the identification of essential microscopic ingredients for such a tunning is a challenging task. In this work, we combine experimental techniques with theoretical calculations at the atomistic level to investigate a variety of neutral and charged point defects along with their response to thermal treatment by optical and transport measurements. We obtain photoluminescence spectra compatible with simulations of Zn vacancies, oxygen interstitials, and complexes combining vacancies of Zn and O. Annealing is an effective way to neutralize the oxygen interstitials, being an effective mechanism to control the ZnO optoelectronic properties. The photosensitive behavior is explored in temperature-dependent electrical responses under different cooling-down modes. The role of both, extended and point defects, in the photoexcitation with energies below and above the bandgap is also discussed. (AU)

• FAPESP's process: 17/11631-2 - CINE: computational materials design based on atomistic simulations, meso-scale, multi-physics, and artificial intelligence for energy applications
• Grantee: Juarez Lopes Ferreira da Silva
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• FAPESP's process: 16/10973-4 - Defects and their features in semiconductor oxides films produced by spray-pyrolysis technique
• Grantee: Marcio Peron Franco de Godoy
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/18719-1 - Electronic carriers dynamics in semiconductor nanostructures
• Grantee: Marcio Daldin Teodoro
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 18/21401-7 - Multi-User Equipment approved in grant 2017/11631-2: cluster computational de alto desempenho - ENIAC
• Grantee: Juarez Lopes Ferreira da Silva
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 18/20729-9 - Formation of Ag Nanoparticles by Laser Irradiation: An ab inicio Investigation
• Grantee: Luis Antônio Cabral
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/19142-2 - Characterization and processing of semiconductor nanostructures and application as devices
• Grantee: Gilmar Eugenio Marques
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 14/07375-2 - Multi-user equipment approved in grant 2013/18719-1: time resolved measurement system
• Grantee: Marcio Daldin Teodoro
• Support Opportunities: Multi-user Equipment Program