Studying and fabricating optical, electrical, and structural properties of p-type Al- and N- co-doped SnO2 (ANTO) films and investigating the photo-electro effect of p-ANTO/n-Si heterojunctions

Abstract

P-type SnO2 films co-doping Al and N increased the high solubility N in the SnO2 host lattice without degrading the crystal structure of the film. The solubility N in the SnO2 host lattice increased with the Al2O3 content in the ATO (Al2O3 doped SnO2) target, and the optimum Al2O3 content was found to be 6 %wt, which corresponds with the best film crystal quality. The optimum optical, electrical, and structural properties of films were achieved at a deposition temperature of 300 °C in a mixture of 50 % Ar and 50 % N2 gas from 6 %wt Al2O3-doped SnO2 target. The Al3+–Sn4+ and N3−–O2− substitution was verified using measurements, such as X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, and XRD patterns. Data regarding the tetragonal rutile to cubic phase transformation indicated the N3−–O2− substitution, while the Al3+–Sn4+ replacement was also verified by the appearance of an additional (101) lattice reflection. The resistivity, hole concentration, and hole mobility of the ANTO-6-50 film achieved the best values were 7.1 × 10−3 Ω cm, 6.24 × 1019 cm−3, and 14.1 cm2 V−1 s−1, respectively. The I–V characteristics of p-ANTO-x-50/n-Si heterojunctions under illumination showed p-type conductive properties of the ANTO-x-50 films and a good reproducible photocurrent response of the p-ANTO-x-50/n-Si heterojunction diodes.