Highly Visible Photoluminescence from Ta-Doped Structures of ZnO Films Grown by HFCVD

Crystals

Eric Reyes-Cervantes¹  Godofredo García-Salgado²  Antonio Coyopol²  Tomás Díaz-Becerril²  Román Romano²  FabiolaG. Nieto-Caballero²  Crisóforo Morales²  Enrique Rosendo²  Reina Galeazzi²  Víctor Herrera² 

[1] Centro Universitario de Vinculación y Transferencia de Tecnología, Prol. de la 24 sur esq. con Av. San Claudio, C.U., Edif. CUVyTT, Puebla 72570, Mexico;Centro de Investigación en Dispositivos Semiconductores, Universidad Autónoma de Puebla, 14 sur y Av. San Claudio, C.U., Edif. IC-5, Puebla 72570, Mexico;

关键词: zinc oxide;    tantalum oxide;    ZnO:Ta doped films;    substitutional alloy;   

DOI  :  10.3390/cryst8100395

来源: DOAJ

【 摘 要 】

Tantalum-doped ZnO structures (ZnO:Ta) were synthesized, and some of their characteristics were studied. ZnO material was deposited on silicon substrates by using a hot filament chemical vapor deposition (HFCVD) reactor. The raw materials were a pellet made of a mixture of ZnO and Ta2O5 powders, and molecular hydrogen was used as a reactant gas. The percentage of tantalum varied from 0 to 500 mg by varying the percentages of tantalum oxide in the mixture of the pellet source, by holding a fixed amount of 500 mg of ZnO in all experiments. X-ray diffractograms confirmed the presence of zinc oxide in the wurtzite phase, and metallic zinc with a hexagonal structure, and no other phase was detected. Displacements to lower angles of reflection peaks, compared with those from samples without doping, were interpreted as the inclusion of the Ta atoms in the matrix of the ZnO. This fact was confirmed by energy dispersive X-ray spectrometry (EDS), and X-ray diffraction (XRD) measurements. From scanning electron microscopy (SEM) images from undoped samples, mostly micro-sized semi-spherical structures were seen, while doped samples displayed a trend to grow as nanocrystalline rods. The presence of tantalum during the synthesis affected the growth direction. Green photoluminescence was observed by the naked eye when Ta-doped samples were illuminated by ultraviolet radiation and confirmed by photoluminescence (PL) spectra. The PL intensity on the Ta-doped ZnO increased from those undoped samples up to eight times.

【 授权许可】

Unknown