Cold spray process to produce Te and TeO2 thin films for gas sensors

Dissertant

Hamdi, Sinan Salman

Thesis advisor

Abd al-Hamid, Ala Ala al-Din

University

University of Technology

Faculty

-

Department

Department of Materials Engineering

University Country

Iraq

Degree

Master

Degree Date

2012

English Abstract

In this work, Tellurium (Te) and Tellurium oxide (TeO2) thin films were successfully prepared by cold spray process using inert atmosphere using helium gas without employing any catalyst.

(Te) and (TeO2) dry powders were sprayed onto different substrates of Si (111) wafer, Al foil, and glass by heating carrier gas at 200,300,400 and 500 °C and 20 bar gas pressure onto substrates of 180±5°C at different angles 0°,30°,45°, to study the effects of these parameters on the resulted microstructure.

The produced thin films were examined by X-ray diffraction analysis (XRD), and Scanning Electron Microscopy (SEM) in addition to Atomic Force Microscopy (AFM).

Scanning electron microscopy images and X-ray diffraction patterns show that the as-synthesized Te has the hexagonal structure, and TeO2 has the tetragonal structure.

SEM images show that the Te thin films have different diameters ranging from 100 to 350 nm, while the TeO2 thin films have different diameters ranging from 200 to 250 nm.

The Te thin film exhibited a high transmission rate of about (95%), while the TeO2 thin film have a maximum transmission rate of about (49%) which allow the products to have potential applications in transparent devices.

The NH3 gas sensors were prepared of the Te and TeO2 thin films ,which were deposited onto (Si (111), Al) substrates.

Thus, the Te and TeO2 thin films demonstrated their potential application in low power consumption device for NH3 sensor.

Main Subjects

Engineering & Technology Sciences (Multidisciplinary)

Topics

• Solids

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-419281