Nanocrystalline transparent SnO₂‐ZnO films fabricated at lower substrate temperature using a low‐cost and simplified spray technique

Abstract

Nanocrystalline and transparent conducting SnO 2 -ZnO films were fabricated by employing an inexpensive, simplified spray technique using a perfume atomizer at relatively low substrate temperature (360±5 °C) compared with conventional spray method. The structural studies reveal that the SnO 2 -ZnO films are polycrystalline in nature with preferential orientation along the (101) plane. The dislocation density is very low (1.48×10 15 lines/m 2 ), indicating the good crystallinity of the films. The crystallite size of the films was found to be in the range of 26-34 nm. The optical transmittance in the visible range and the optical band gap are 85% and 3.6 eV respectively. The sheet resistance increases from 8.74 kΩ/ to 32.4 kΩ/ as the zinc concentration increases from 0 to 40 at.%. The films were found to have desirable figure of merit (1.63×10-2 (Ω/ ) -1 ), low temperature coefficient of resistance (-1.191/K) and good thermal stability. This simplified spray technique may be considered as a promising alternative to conventional spray for the massive production of economic SnO 2 -ZnO films for solar cells, sensors and opto-electronic applications.

Detailed investigation of submicrometer-sized grains of chemically sprayed (Sn1−xAlx, O2) (0≤x≤0.085) thin films

“…4B according to (2 0 0) and (2 1 1) magnitude as those reported by Ravichandran [24]. Similar shape was observed according to (2 1 1) direction [27].…”

“…These oscillations might be due to the difference in film thickness. The oscillations were observed in 2.31, 12.05 and 18.56% Al-doped SnO 2 produced by sol gel technique as reported by Ahmed [18,19], and by Ravichandran in SnO 2 -ZnO films [24]. Our samples exhibited significant fluctuations of the transmittance in VIS-IR spectrum around an average equal to 82%.…”

“…The same grain size was found by Wei for spin coated Al:SnO 2 films [27]. The dislocation length per unit volume, was defined by the dislocation density ı (lines nm −2 ), which measured the proportion of defects in a crystal as reported by Ravichandran [24]. The dislocation density was expressed as follows,…”

“…3 depicted the variation of lattice parameters (a) and (c) versus Al doping levels. The lattice parameters a and c were determined from the expression 1 according to (2 0 0) direction [24],…”

Self-assembly of disk-like multiring ZnO–SnO2 colloidal nanoparticles

“…In order to gain better performances, a number of ZnO-SnO 2 composites with regular nanostructures have been synthesized by a number of preparation methods, such as high-pressure [10], spray [11], hydrothermal [12], solid-state chemical [13] and chemical vapor deposition [14]. Thus various nanostructures of ZnO-SnO 2 products are produced, e.g.…”