Study of Charged Liquid Cluster Beam Generation and Application to Processing of Thin Films and Nanoparticles

Ryu, Choon Kun

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https://hdl.handle.net/2142/82894 Copy

Description

Title

Study of Charged Liquid Cluster Beam Generation and Application to Processing of Thin Films and Nanoparticles

Author(s)

Ryu, Choon Kun

Issue Date

1997

Doctoral Committee Chair(s)

Kim, Kyekyoon

Department of Study

Materials Science and Engineering

Discipline

Materials Science and Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Engineering, Materials Science

Language

eng

Abstract

The CLCB spraying was applied to processing of thin films and nanoparticles. Silica nanospheres were fabricated using the CLCB technique. The median size of the resulting silica nanospheres was around 10 nm and the smallest size observed within the SEM resolution limit was 5 nm. Quantum wires of GaAs and silicon nanotips were fabricated by combining CLCB deposition of silica nanospheres and reactive ion etching. The median size of the quantum wires is 50 nm. Photoluminescence (PL) measurements indicated a blue shift of 4.5 nm corresponding to an 8-meV energy shift was observed due to quantum size effect. The CLCB technique was applied to the fabrication of ZnO thin films on silicon substrates with a thin layer of native oxide. The films were very uniform, densely packed, and c-axis-oriented polycrystalline. The electrical resistivities of the annealed films ranged from $7.99 \times 10\sp{-3}$ to $1.60 \times 10\sp{-2}\ \Omega$-cm. The electron carrier concentrations were in the range of 3.33-5.35 $\times\ 10 \sp{19}$ cm$\sp{-3}$ and the mobilities were 7.30-19.07 cm$\sp2$V$\sp{-1}$s$\sp{-1}.$ Optically active, highly concentrated Er$\sp{3+}$-$\rm Al\sp{3+}$ co-doped silica thin films were fabricated on fused silica substrates by sol-gel method. Photoluminescence (PL) measurements indicated that Er ions were optically active in all films of different Er concentrations. A broad-band peak was observed at 1531 nm with the full-width at half-maximum (FWHM) of 42 nm due to the $\sp4$I$\rm\sb{13/2} \to \sp4$I$\sb{15/2}.$ transition. The PL peak showed maximum intensity at an Er concentration of 8535 ppm. This implies the concentration quenching at higher Er$\sp{3+}$ concentrations.

Graduation Semester

1997

Type of Resource

text

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