Studying some physical properties of bismuth oxide films and their applications in laser and optoelectronics

Dissertant

al-Wazni, Marwah Sabah Muhsin

Thesis advisor

al-Wisi, Evan Tariq

University

University of Technology

Faculty

-

Department

Applied Sciences Department

University Country

Iraq

Degree

Master

Degree Date

2013

English Abstract

In the present work, nano and micro structures of bismuth oxide thin films, prepared by reactive Q-switching pulsed laser deposition was studied using (9 nsec), (1.06 μm) Nd-YAG laser as an ablating tool for Bi target under the O2 environment on silicon and glass substrates.

Optimum conditions based on laser fluence, oxygen back ground pressure and substrate temperatures were selected.

Structural, optical, electrical and surface morphology properties of Bi2O3 films were investigated and analyzed extensively with respect to growth conditions.

Films prepared were used to fabricate photovoltaic heterojunction devices using P-type silicon, (111) oriented substrates at three different active layer thicknesses.

The X-Ray diffraction spectra at optimum laser fluence of (7.8J/cm2), oxygen pressure of (200 mbar) and Tsub of (523K) revealed that strong peaks related to tetragonal phase at 2θ=28o at (201) plane and monoclinic phase at 2θ=27.5o reflected from (121) plane of the Bi2O3 thin film.

The optical properties of Bi2O3 films at optimum condition showed high transparency and the estimated energy gap found to be about (2.6 eV).

The electrical properties of prepared films confirm n-type nature.

The electrical resistively of films prepared at different substrate temperature found to be in range of (99.85-136.86 Ω.cm) at room temperature (R.T).

Surface morphology results using; AFM and SEM, show an average grain size of Bi2O3 films at optimum condition was around (120nm).

In order to characterize the prepared device, the electrical properties were measured.

Capacitance- Voltage results showed that all junctions are of abrupt type.

The built-in potential was varying with the active layer thicknesses from (1.8 to 1.5 V.) Detector parameters results indicate that the fabricated detectors gave a responsivity in range of (0.14 A/W - 0.23A/W) at peak wavelength of (880nm), while maximum detectivity of (1.4*1011 W-1.

cm.

Hz1/2-1.6*1011 W-1.

cm.

Hz1/2)

Main Subjects

Physics

Topics

• Physical properties
• Optical properties

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-418101