Reparation of SI ZNO junction for UV detection

Other Title(s)

تحضير وصلة سيليكون أوكسيد الزنك لكشف الأشعة فوق البنفسجية

Dissertant

Naum, Fatin Imad

Thesis advisor

al-Bassam, Sudad Salman Ahmad
Suhayl, Abd Allah Muhsin

Comitee Members

Hassani, A. S.
al-Tamimi, Nadhirah Abbas Ali
Agha, Ahmad Kamal Ahmad Khidr

University

University of Baghdad

Faculty

College of Science

Department

Department of Physics

University Country

Iraq

Degree

Master

Degree Date

2012

English Abstract

-In this work, Zinc Oxide (ZnO) film deposited on Porous Silicon (PSi) is fabricated to form photovoltaic detector.

The ZnO thin films are prepared by thermal chemical spray pyrolysis technique and deposited on the porous silicon substrate.

The porous silicon is prepared by photochemical etching process at different etching times (30, 60 and 90min).

The structure properties of the films have been studied by using X-ray diffraction (XRD) and found to be polycrystalline of hexagonal structure with strong crystalline orientation at (002).

The optical measurements showed that ZnO films have direct energy band gap (Eg).

The optical energy gap is calculated by two techniques, the absorption spectrum which gives a value 3.21eV, whereas energy gap Eg value from the Photoluminescence spectrum is found to be 3.47eV.

The surface morphology studies demonstrate that the ZnO nanofilm deposited on PSi is improved with respect to the film deposited on glass substrate.

The electrical properties of the prepared films were studied at different etching times (30, 60 and 90 min.).

The Hall measurements show that the ZnO film deposited on glass substrate is n-type semiconductor, whereas the film deposited on nanospikes silicon layer shows intrinsic ZnO.

The capacitancevoltage measurements have been studied at frequency of 103 Hz, The value of built-in potential increases from 0.6 to 1.04 Volt with increasing etching time, while the values of depletion width increase from 29nm to 40nm with increasing etching time.

The current-voltage characteristics have been studied for the prepared heterojunction under dark condition, it was found that the ideality factor increases with increasing etching time from (1.1-13.4).

Under illumination, the photocurrent increase and response time of the fabricated ZnO UV detector was measured and was found that the detect pulse has 1μs rise time and a fall time of about 5 μs.

Main Subjects

Physics

No. of Pages

79

Table of Contents

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Language

English

Data Type

Arab Theses

Record ID

BIM-755323