Effect of Surface Passivation on Electrical Properties of Pd-F:SnO2 Thin Films Prepared by Spray Pyrolysis Technique

Coatings

Patrick Mwathe¹  Robinson Musembi³  Mathew Munji¹  Victor Odari²  Lawrence Munguti¹  Alex Ntilakigwa³  John Nguu³  Boniface Muthoka³ 

[1] Department of Physics, Kenyatta University, P.O. Box 43844, 00100 Nairobi, Kenya; E-Mails:;Department of Physics, Masinde Muliro University of Science and Technology, P.O. Box 190, 50100 Kakamega, Kenya; E-Mail:;Department of Physics, University of Nairobi, P.O. Box 30197, 00100 Nairobi, Kenya; E-Mails:

关键词: spray pyrolysis;    fluorine doping;    palladium doping;    codoping;    palladium and fluorine co-doping;    annealing;    passivation;    F-co-doped Pd:SnO₂ (Pd-F:SnO₂);   

DOI  :  10.3390/coatings4040747

来源: mdpi

【 摘 要 】

Pd-F:SnO₂ thin films have been prepared by spray pyrolysis technique. Optimization has been done by doping SnO₂ with palladium at varying levels of concentration and then recording sheet resistance. The sheet resistivity has been observed to decrease gradually as at% Pd concentration is increased; an optimum sheet resistivity value of 2.71 × 10⁻² Ω cm has been recorded. The decrease in sheet resistivity has been attributed to presence of Pd ions which contribute in increment of charge carrier density. Using the optimum value of at% Pd doping, the same procedure has been repeated to study the effect of fluorine on Pd:SnO₂; an optimum value of 1.64 × 10⁻⁴ Ω cm sheet resistivity has been recorded. This decrease has been attributed to substitution of O⁻ with those of fluorine hence improving charge carrier density. The effect of passivation has been studied by comparing as prepared, annealed and passivated Pd-F:SnO₂ thin films. Annealing has been observed to decrease the sheet resistivity to 1.21 × 10⁻⁴ Ω cm, while passivation has the effect of increasing the sheet resistivity to 1.53 × 10⁻⁴ Ω cm which is attributed to effects resulting from annealing the samples in nitrogen gas atmosphere.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.