TY - GEN
T1 - Optical and electrical properties of TiO2 nanotubes grown by titanium anodization
AU - Alivov, Yahya
AU - Kuryatkov, Vladimir
AU - Pandikunta, Mahesh
AU - Rajanna, Gautam
AU - Johnstone, D.
AU - Bernussi, Ayrton
AU - Nikishin, Sergey
AU - Fan, Z. Y.
PY - 2009
Y1 - 2009
N2 - In this work we investigated the structural, electrical, and optical properties of titanium dioxide (TiO2) nanotubes (NTs) formed by electrochemical anodization of Ti metal sheets in NH4F+glycerol electrolyte at different anodization voltages (Va) and acid concentrations. Our results revealed that TiO2 NTs can be grown in a wide range of anodization voltages from 10 V to 240 V. The maximum NH 4F acid concentration, at which NTs can be formed, decreases with the anodization voltage, which is 0.7% for Va<60V, and decreases to 0.1% at Va =240 V. Glancing angle X-ray diffraction (GAXRD) experiments show that as-grown amorphous TiO2 transforms to anatase phase after annealing at 400°C, and further transforms to rutile phase at annealing temperatures above 500°C. Samples grown in 30-120 voltage range have higher crystal quality as seen from anatase (101) peak intensity and reduced linewidth. The electrical resistivity of the NTs varies with V a concentration and increases by eight orders of magnitude when Va increases from 10 V to 240 V. This is consistent with cathodoluminescense studies which showed improved optical properties for samples grown in this voltage range. Optical properties of samples were also studied by low temperature photoluminescence. Temperature dependent I-V and photo-induced current transient spectroscopy were employed to analyze electrical properties and defect structure on NT samples.
AB - In this work we investigated the structural, electrical, and optical properties of titanium dioxide (TiO2) nanotubes (NTs) formed by electrochemical anodization of Ti metal sheets in NH4F+glycerol electrolyte at different anodization voltages (Va) and acid concentrations. Our results revealed that TiO2 NTs can be grown in a wide range of anodization voltages from 10 V to 240 V. The maximum NH 4F acid concentration, at which NTs can be formed, decreases with the anodization voltage, which is 0.7% for Va<60V, and decreases to 0.1% at Va =240 V. Glancing angle X-ray diffraction (GAXRD) experiments show that as-grown amorphous TiO2 transforms to anatase phase after annealing at 400°C, and further transforms to rutile phase at annealing temperatures above 500°C. Samples grown in 30-120 voltage range have higher crystal quality as seen from anatase (101) peak intensity and reduced linewidth. The electrical resistivity of the NTs varies with V a concentration and increases by eight orders of magnitude when Va increases from 10 V to 240 V. This is consistent with cathodoluminescense studies which showed improved optical properties for samples grown in this voltage range. Optical properties of samples were also studied by low temperature photoluminescence. Temperature dependent I-V and photo-induced current transient spectroscopy were employed to analyze electrical properties and defect structure on NT samples.
UR - http://www.scopus.com/inward/record.url?scp=77954263470&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77954263470&partnerID=8YFLogxK
U2 - 10.1557/proc-1178-aa09-27
DO - 10.1557/proc-1178-aa09-27
M3 - Conference contribution
AN - SCOPUS:77954263470
SN - 9781617383977
T3 - Materials Research Society Symposium Proceedings
SP - 85
EP - 90
BT - Semiconductor Nanowires - Growth, Size-Dependent Properties and Applications
PB - Materials Research Society
T2 - 2009 MRS Spring Meeting
Y2 - 13 April 2009 through 17 April 2009
ER -