Preparation and characteristics study of ZnO-Si heterojunction

Dissertant

Jasim, Muhammad Jamal

Thesis advisor

Nayif, Adi Muhsin

University

University of Technology

Faculty

-

Department

Applied Sciences Department

University Country

Iraq

Degree

Master

Degree Date

2012

English Abstract

In this thesis preparation of good quality transparent conductive ZnO thin films by post-oxidation of vacuum evaporated Zn, on glass and silicon (p- type) as substrates, the oxidation was achieved in a short time (90 sec) which is known as rapid thermal oxidation.

One growth parameter that has been considered to specify the optimum conditions, the film thickness are (200, 300, 400, and 500 nm).

The structural, optical, electrical and photovoltaic properties of ZnO films are investigated and analyzed extensively with respect to growth condition, The XRD spectra revealed a high oriented grain in the (002) lattice system which is hexagonal wurtzite and proved that the ZnO films have a polycrystalline structure.

Also, The atomic force microscopy AFM micrographs show that all films have a homogeneous surface morphology and it appears, to change significantly as a function of thickness, ZnO film has high transmittance in visible region, the energy gap decreases as the thickness increases.

The FTIR spectra indicate the existence of the distinct characteristic absorption peak at 472.56 cm1 for Zn-O stretching modes.

Hall effect measurements are changed with thickness where concentration (ND) and mobility of carriers charge (/itf) increase with the thickness increase.

Thickness effect was apparent through (I-V) measurements of ZnO/si films with the increase thickness.

The photovoltaic properties con£rmed that the photovoltaic depends strongly on the bias voltage and the amount of current produced by a photovoltaic device which is directly related to the number of photons absorbed.

C-V results demonstrated that the fabricated heterojunction is of abrupt type.

Also, the width of the depletion layer (W) follows the same behavior (ظاا ^)while the charge carrier density (Nd) was increased with the thickness increase.

Main Subjects

Physics

Topics

• Solids
• Oxides
• Zinc oxide

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-419702