Improvement of electrical stability of polycrystalline ZnO thin films via intentional post-deposition hydrogen doping

• Published in: Thin solid films 2006-08, Vol.513 (1), p.148-151
• Main Authors: Myong, Seung Yeop, Park, Sang Il, Lim, Koeng Su
• Format: Article
• Language: English
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fourier transform infrared spectroscopy (FTIR); Hydrogen; Lattice dynamics; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Photoluminescence; Physics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Zinc oxide
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2006.01.066

We investigate the hydrogen doping effect on polycrystalline ZnO thin films prepared by the photoassisted metalorganic chemical vapor deposition technique. In situ post-deposition hydrogen doping was performed using mercury-sensitized photodecomposition of hydrogen gas. From Fourier transform infrared spectra, we observe small changes in O–H bond-stretching local vibrational modes as a result of hydrogen doping. The photoluminescence measurements reveal that intentional hydrogen doping significantly suppresses nonradiative recombination centers in the ZnO films. The undoped ZnO film reveals a heavily n-type as-grown conductivity due to the high hydrogen content, but it is unstable in a humid air atmosphere. However, the electrical stability is significantly improved as a result of hydrogen doping.