Low-cost VO2(M1) thin films synthesized by ultrasonic nebulized spray pyrolysis of an aqueous combustion mixture for IR photodetection
Tadeo, IJ; Mukhokosi, EP; Krupanidhi, SB; Umarji, A
| HERO ID | 6310359 |
|---|---|
| In Press | No |
| Year | 2019 |
| Title | Low-cost VO2(M1) thin films synthesized by ultrasonic nebulized spray pyrolysis of an aqueous combustion mixture for IR photodetection |
| Authors | Tadeo, IJ; Mukhokosi, EP; Krupanidhi, SB; Umarji, A |
| Journal | RSC Advances |
| Volume | 9 |
| Issue | 18 |
| Page Numbers | 9983-9992 |
| Abstract | We report detailed structural, electrical transport and IR photoresponse properties of large area VO2(M1) thin films deposited by a simple cost-effective two-step technique. Phase purity was confirmed by XRD and Raman spectroscopy studies. The high quality of the films was further established by a phase change from low temperature monoclinic phase to high temperature tetragonal rutile phase at 68 °C from temperature dependent Raman studies. An optical band gap of 0.75 eV was estimated from UV-visible spectroscopy. FTIR studies showed 60% reflectance change at λ = 7.7 μm from low reflectivity at low temperature to high reflectivity at high temperature in a transition temperature of 68 °C. Electrical characterization showed a first order transition of the films with a resistance change of four orders of magnitude and TCR of -3.3% K-1 at 30 °C. Hall-effect measurements revealed the n-type nature of VO2 thin films with room temperature Hall mobility, μ e of 0.097 cm2 V-1 s-1, conductivity, σ of 0.102 Ω-1 cm-1 and carrier concentration, n e = 5.36 × 1017 cm-3. In addition, we fabricated a high photoresponsive IR photodetector based on VO2(M1) thin films with excellent stability and reproducibility in ambient conditions using a low-cost method. The VO2(M1) photodetector exhibited high sensitivity, responsivity, quantum efficiency, detectivity and photoconductive gain of 5.18%, 1.54 mA W-1, 0.18%, 3.53 × 1010 jones and 9.99 × 103 respectively upon illumination with a 1064 nm laser at a power density of 200 mW cm-2 and 10 V bias voltage at room temperature. |
| Doi | 10.1039/c9ra00189a |
| Pmid | 35520889 |
| Wosid | WOS:000466754600012 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Language Text | English |