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Optoelectronics properties of tungsten oxide nanoparticle networks deposited by flame spray pyrolysis

Published online by Cambridge University Press:  26 June 2018

Domenico Caputo*
Affiliation:
Department of Information Engineering, Electronics and Telecommunications, University of Rome Sapienza, Rome, Italy.
Shaul Ajò
Affiliation:
Department of Information Engineering, Electronics and Telecommunications, University of Rome Sapienza, Rome, Italy.
Giampiero de Cesare
Affiliation:
Department of Information Engineering, Electronics and Telecommunications, University of Rome Sapienza, Rome, Italy.
Alessio Buzzin
Affiliation:
Department of Information Engineering, Electronics and Telecommunications, University of Rome Sapienza, Rome, Italy.
Renheng Bo
Affiliation:
Nanotechnology Research Laboratory, Research School of Engineering, Australian National University, Canberra, ACT, Australia.
Antonio Tricoli
Affiliation:
Nanotechnology Research Laboratory, Research School of Engineering, Australian National University, Canberra, ACT, Australia.
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Abstract

In this work, we present the optoelectronic characterization of pure tungsten oxide nanoparticle networks synthesized and self-assembled by flame spray pyrolysis. Current-voltage measurements performed in dark conditions indicate the presence of trapping and de-trapping phenomena from defects inside the energy gap. The presence of defects is confirmed by the time evolution of the photocurrent, measured under monochromatic radiation at 420 nm. After illuminating the WO3 films with light, the current increases exponentially with a time constant independent on the applied voltage. This behavior is ascribed to the presence of defects lying at 1.1 eV below the conduction band of WO3 (bandgap of ca. 2.9 eV). When the illumination is terminated, the photocurrent shows an exponential decrease, once again independently on the applied voltage. The defect level corresponding to this relaxation process corresponds to 0.92eV below the conduction band.

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Articles
Copyright
Copyright © Materials Research Society 2018 

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References

Granqvist, C.G., “Handbook of Inorganic Electrochromic Materials”, (Elsevier 2002) pp. 175205.Google Scholar
Shim, H. S., Kim, J. W., Sung, Y.E. and Kim, W. B., Solar Energy Materials and Solar Cells, 93, 20622068 (2009).CrossRefGoogle Scholar
Chaudhari, G.N., Bende, A.M., Bodade, A.B., Patil, S.S. and Sapkal, V.S., Sensors and Actuators B: Chemical, 115, 297302 (2006).CrossRefGoogle Scholar
Righettoni, M. and Tricoli, A., J. Breath Research, 5, 037109 (2011).CrossRefGoogle Scholar
Azimirad, R., Akhavan, O. and Moshfegh, A. Z., J. Electrochem. Soc., 153, E11E16 (2006).CrossRefGoogle Scholar
Aly, S. A., Defect and Diffusion Forum, 11, 295296 (2009).Google Scholar
Seman, M. and Wolden, C. A., J. Vacuum Science and Technology A, 21, 1927 (2003).CrossRefGoogle Scholar
Perednis, D. and Gauckler, L. J., Journal of electroceramics 14, 103111 (2005).CrossRefGoogle Scholar
Patil, P.S., Patil, P. R. and Ennaoui, E. A., Thin solid films, 370, 3844 (2000).CrossRefGoogle Scholar
Aly, S. A., Akl, A. A. and Mahmoud, D. H., Int. J. New. Hor. Phys., 2, 4752 (2015).Google Scholar
Ji, R., Zheng, D., Zhou, C., Cheng, J., Yu, J. and Li, L., Materials, 10, 820 (2017).CrossRefGoogle Scholar
Hao, J., Studenikin, S. A. and Cocivera, M., J. of Appl. Phys., 90, 50645069 (2001).CrossRefGoogle Scholar
Mehmood, F., Pachter, R., Murphy, N. R., Johnson, W. E. and Ramana, C. V., Journal of Applied Physics, 120, 233105 (2016).CrossRefGoogle Scholar