Effect of Annealing Temperature on Optical and Electrical Properties of ZnO/Ag/ZnO Multilayer Films for Photosensor

In this study, multilayer transparent conductive films were formed by depositing titanium dioxide (TiO 2 ) and zinc oxide (ZnO) or indium tin oxide (ITO) on a glass substrate by radiofrequency magnetron sputtering using different sputtering parameters, and by depositing niobium (Nb) of 99.99% purity as an intermediate layer between the two oxide layers by DC magnetron sputtering. It was found that the amount of crystals in all the multilayer film structures increases with the annealing temperature, the TiO 2 /Nb/ITO (TNI) multilayer film structure has the best electrical properties when annealed at 500 °C, with the resistivity being 9.22 × 10 −4 Ω-cm (with the highest average transmittance being 87.85% at the annealing temperature of 300 °C), and the TNI multilayer film structure also has the highest figure of merit (FOM), i.e., 3.88 × 10 −3 Ω −1 . However, the TiO 2 /Nb/ZnO (TNZ) film annealed at 500 °C had the resistivity of 1.63 × 10 −2 Ω-cm, the transmittance of 81.20%, and the FOM of 1.66 × 10 −8 Ω −1 . The results showed that the TNI multilayer film had the best optical and electrical properties. The results of this study indicate that such multilayer film structures are suitable for use as photoelectric sensors.

Section: Introductionmentioning

confidence: 99%

Effects of Annealing Temperature on Optical and Electrical Properties of Different Multilayer Film Structures for Photoelectric Sensors

Tsai,

Liu,

Guo

et al. 2023

“…(4)(5)(6)(7)(8)(9) Accordingly, the problem of improving the electrical performance of ZnO thin films through doping with metallic elements such as Al, Ga, Ag, Ti, Zr, and Mo has attracted significant attention in recent years. (10)(11)(12)(13)(14)(15) In such methods, the doped atoms substitute for the Zn atoms in the ZnO crystal structure and produce free electrons in the conduction band, which lower the electrical resistivity. One of the most widely used dopants of ZnO nanostructures is manganese (Mn) due to its large number of free electrons in the electric band.…”

Section: Introductionmentioning

confidence: 99%

Optical and Electrical Properties of Mn-doped and Mn–Al co-doped ZnO Thin Films Annealed at Different Temperatures for Photosensor Applications

Yen¹,

Chen²,

Lai³

et al. 2022

Self Cite

Mn-doped and Mn-Al co-doped zinc oxide (ZnO) thin films were deposited on glass substrates by RF magnetron sputtering at room temperature. The X-ray diffraction results revealed that both films consisted of a single phase and had a wurtzite structure with a c-axis orientation. The electrical properties, transmittance characteristics, surface properties, and crystal structures of the films were investigated following annealing at temperatures ranging from 200 to 500 °C. The results showed that the as-deposited Mn:ZnO thin film had an average transmittance of 83%. The transmittance increased to 85% following annealing at 500 °C. The as-deposited Mn-Al co-doped ZnO thin film had a low transmittance of only 40%. However, after annealing at 500 °C, the transmittance increased to 83%. The annealed Mn-Al:ZnO thin film also showed a low electrical resistivity of 1.75 × 10 −3 Ω•cm, an electron mobility of 20.8 cm 2 V −1 s −1 , and a carrier concentration of 5.3 × 10 20 cm −3 . Scanning electron microscopy (SEM) results showed that the crystal size of both thin films increased following annealing. Owing to their good optical and electrical properties, the annealed Mn-Al:ZnO thin films can be used as photosensor materials.

“…(1)(2)(3) Zinc oxide has been widely utilized for domestic and industrial applications such as liquid crystal displays, light-emitting diodes, (4) and sensors. (5)(6)(7)(8)(9) Indium tin oxide (ITO) thin films were the first materials to be widely used in these electrical devices. However, ZnO is a TCO with a wide direct band gap of ~3.37 eV at room temperature (RT) and has low cost and toxicity, low electrical resistivity, and high optical efficiency.…”

Section: Introductionmentioning

confidence: 99%

Effects of Annealing Temperature on Structural and Optoelectronic Properties of Zr-doped ZnO Thin Films for Photosensors

Yen¹,

Chen²,

Lai³

et al. 2021

Self Cite

We investigated the effects of the annealing temperature on the optoelectronic properties of Zr-doped ZnO (ZZO) thin films deposited on glass substrates by radio frequency sputtering and annealed at 200, 300, and 400 °C. It was found by X-ray diffraction analysis that all the deposited thin films had a hexagonal crystal structure with polycrystalline grains oriented along the (0 0 2) direction. Furthermore, the film annealed at 400 ℃ had the lowest resistivity among the films due to the growth of grains, as well as the lowest resistivity of 1.5 × 10 −2 Ω•cm, a mobility of 35 cm 2 V −1 s −1 , and a carrier concentration of 4.2 × 10 19 cm −3 . It also had a maximum transmittance of 95% and an energy gap of 3.2 eV. These results show that ZZO thin films subjected to annealing at 400 ℃ are promising for use as stable photosensors.