TY - JOUR
T1 - Crystallization from amorphous structure to hexagonal quantum dots induced by an electron beam on CdTe thin films
AU - Becerril, M.
AU - Zelaya-Angel, O.
AU - Medina-Torres, A. C.
AU - Aguilar-Hernández, J. R.
AU - Ramírez-Bon, R.
AU - Espinoza-Beltran, F. J.
N1 - Funding Information:
The authors thank to Ings. N. Castillo, M. Guerrero, Z. Rivera and A. B. Soto for their technical assistance. This work was partially supported by the CONACyT—México.
PY - 2009/2/15
Y1 - 2009/2/15
N2 - Amorphous cadmium-telluride films were prepared by rf sputtering on Corning 7059 glass substrates at room temperature. The deposition time was 10 and 12 h with a thickness of 400 and 480 (±40 nm), respectively. As-prepared films were amorphous according to X-ray diffraction (XRD) patterns, but a win-fit-software analysis of the main XRD broad band suggests a wurtzite structure at short range. Transmission electron microscopy (TEM) at 200 keV produces crystallization of the amorphous CdTe. The TEM-electron beam induces the formation of CdTe quantum dots with the wurtzite hexagonal structure (the metastable structure of CdTe) and with ∼6 nm of average grain size. As effect of a probable distortion of the CdTe crystalline lattice, the unit cell volume (UCV) shrinks to about 30% with respect to the bulk-UCV of CdTe. Besides, the energy band gap increases as expected, according to literature data on quantum confinement.
AB - Amorphous cadmium-telluride films were prepared by rf sputtering on Corning 7059 glass substrates at room temperature. The deposition time was 10 and 12 h with a thickness of 400 and 480 (±40 nm), respectively. As-prepared films were amorphous according to X-ray diffraction (XRD) patterns, but a win-fit-software analysis of the main XRD broad band suggests a wurtzite structure at short range. Transmission electron microscopy (TEM) at 200 keV produces crystallization of the amorphous CdTe. The TEM-electron beam induces the formation of CdTe quantum dots with the wurtzite hexagonal structure (the metastable structure of CdTe) and with ∼6 nm of average grain size. As effect of a probable distortion of the CdTe crystalline lattice, the unit cell volume (UCV) shrinks to about 30% with respect to the bulk-UCV of CdTe. Besides, the energy band gap increases as expected, according to literature data on quantum confinement.
KW - A1. Crystal morphology
KW - A1. Nanostructures
KW - A1. X-ray diffractions
KW - B2. Semiconducting II-VI materials
UR - http://www.scopus.com/inward/record.url?scp=61349148692&partnerID=8YFLogxK
U2 - 10.1016/j.jcrysgro.2008.12.056
DO - 10.1016/j.jcrysgro.2008.12.056
M3 - Artículo
SN - 0022-0248
VL - 311
SP - 1245
EP - 1249
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
IS - 5
ER -