Porous GaN for Gas Sensing Application

Abstract:

Porous wide bandgap semiconductors have been widely studied in the last decade due to their unique properties compared to the bulk crystals. GaN received attention from the researchers as an ideal material to fabricate chemical sensing devices due to its excellent properties such as high thermal, mechanical and chemical stabilities, large band gap and high breakdown voltage. In this work, porous GaN was prepared by ultraviolet (UV) assisted electroless chemical etching method. The samples used in this study were commercial n-GaN grown on sapphire (Al₂O₃) substrates. The samples were initially cleaned in 1:20 NH₄OH:H₂O, followed by second cleaning in 1:50 HF:H₂O and final cleaning in 3:1 HCl: HNO₃ and these samples were etched in HF:H₂O₂:CH₃OH under UV illumination for 60 minutes. The structural properties was characterized using Scanning Electron Microscope (SEM). Hydrogen sensor was subsequently fabricated by depositing Pd Schottky contact onto the porous GaN sample. The effect of sensing dilute H₂ gas with different concentration which is 1% and 2% H₂ in a N₂ gas ambient was analyzed. The Schottky barrier height of the gas sensor samples was reduced upon exposure to gas. The porous GaN resulted better sensitivity compared to the as grown GaN sample in H₂ gas sensing.

• Periodical: Advanced Materials Research (Volume 1043)
• Pages: 50-56
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1043.50
• Online since: October 2014
• Authors: Nurul Huda Mohd Noor, Zainuriah Hassan, Fong Kwong Yam
• Keywords: Electroless Chemical Etching, Gas Sensing, Pd Schottky Contact, Porous GaN

References

[1] Shuji Nakamura and Shigefusa F. Chichibu, in: Introduction to N itride Semiconductor Blue lasers and light emitting diodes (Taylor and F rancis, 2000).

DOI: 10.1201/9781482268065

[2] Y. Alifragis, G. Konstantinidis, A. Georgakilas and N. Chaniotakis: Electroanalysis, 17 (2005), p.527.

DOI: 10.1002/elan.200403191

[3] J. Schwalwig, G. Muller, U. Karrer, M. Eichkoff, O. Ambacher, M. Stutzmann, L. Gorgens and G. Dollinger, Appl. Phys. Lett, 80 (2002), p.1222.

[4] M. Ali, V. Cimalla, V. Lebedev, H. Romanus, V. Tilak, D. Merfeld, P. Sandvik and O. Ambacher, Science Direct, 113 (2006), pp.797-804.

DOI: 10.1016/j.snb.2005.03.019

[5] J. A. Manthey, K. Grohman, and N. Guthrie, Curr. Med. Chem., 8 (2001), pp.135-153.

[6] C. F. Coombs, Electronic Instruments Handbook (1999).

[7] B. P Luther, S. D. Wolter and S. E. Mohney: Sensors and Actuator, B56 (1999), pp.164-168.

[8] J. Song and W. Lu: Solid State Electronics, 49 (2005), p.1330 – 1334.

[9] A. P Vajpeyi, S. Tripathy, S. J Chua and E. A Fitzgerald, Physica E: Low-dimensional Systems and Nanostructures, 28 (2005) , pp.141-149.

DOI: 10.1016/j.physe.2005.03.007

[10] J. Diaz, L. T. Williamson and X. Guo, A. Sood and W. P. Bohn, NRC – CSTI, 514 (2006), pp.120-126.

[11] J. Wang, D. G Zhao, Y. P. Sun, L. H. Duan, Y. T Wang, S. M Zhang, H Yang, Shengqiang Zhou, M. Wu and J. Phys. D: Phys, 36 (2003), p.1018 – 1022.

[12] E.H. Rhoderick and R.H. Williams, Metal Semiconductor Contacts, 2nd ed, Clarendon Press, Oxford (1988).

[13] J. Kim, B. P. Gila, G. Y. Chung, C. R. Abernathy, S. J. Pearton and F. Ren, Solid States Electronics, 47 (2003), pp.1069-1073.

DOI: 10.1016/s0038-1101(02)00485-9

[14] M. Ali, V. Cimalia, V. Lebedev, H. Romanus, V. Tilak, D. Merfeld, P. Sandvik and O. Ambacher, Sensors and Actuators, B113 (2006), pp.797-804.

DOI: 10.1016/j.snb.2005.03.019

[15] L. Wang, M. I. Nathan, T. H. Lim, M. A. Khan and Q. Chen, Appl. Phys. Lett, 68 (1996), p.1267.

[16] M. Ali, V. Cimalia, V. Lebedev, H. Romanus, V. Tilak, D. Merfeld, P. Sandvik and O. Ambacher, Sensors and Actuators, B113 (2006), pp.797-804.

DOI: 10.1016/j.snb.2005.03.019