Characterization of (CuInSeTe, CuInSSe and CuInSTe)‎ CdS Heterojunction

Other Title(s)

خواص المفارق الهجينة (CuInSeTe, CuInSSe and CuInSTe)‎ CdS Heterojunction

Dissertant

Umran, Dua Adil

Thesis advisor

Hasan, Bushra Abbas
al-Hilli, Muzaffar Fuad Jamil

Comitee Members

Shaban, Salma M.
Hirmiz, G. Y.
Muhammad, Muzaffar A.

University

University of Baghdad

Faculty

College of Science

Department

Department of Physics

University Country

Iraq

Degree

Master

Degree Date

2006

English Abstract

The preparation of (CuInSeTe CuInSSe and CuInSTe) thin films at different substrates temperatures (303, 373 and 423) K with average thickness (700±8) nm have been performed by thermal evaporation technique on glass substrate and under vacuum of 10-5 mbar with rate of deposition 25nm/sec.

The structures of (CuInSeTe CuInSSe and CuInSTe,) bulk and films have been studied by X–ray diffraction technique.

The result reveals that the prepared alloys and thin films which were deposited at both substrate temperatures (373and 423) K have polycrystalline structures whereas as deposited thin films are amorphous. The optical measurement shows that the (CuInSeTe CuInSSe and CuInSTe) films have direct energy gap and the energy gap (Eg opt) increases with the increase of substrate temperatures for all samples.

Also the optical constants such as refractive index (n), extinction coefficient (k) and dielectric constant (εr, εi) have been calculated. Resistivity and Hall Effect measurements show that of (CIS'T, CIS'S and CIST) thin films is p-type semiconductors, the concentration of charge carriers, D.C conductivity decreases with increasing of depositing temperature. The capacitances at reverse bias of (CuInSeTe/CdS CuInSSe/CdS, and CuInSTe/CdS) heterojunction are measured at frequency (10 KHz, 100 KHz and 1 MHz) the measurements indicate that all heterojunction are abrupt.

The capacitance decreases with increasing the reverse bias voltage, and substrates temperatures, while the built–in voltage value decrease with the increase of substrates temperatures. The current–voltage characteristics of (CuInSeTe/CdS, CuInSSe/CdS, and CuInSTe/CdS) heterojunction show that the forward current at dark condition varies approximately exponentially with applied voltage and the junction is coinciding with recombination–tunneling model.

Under illumination, the photocurrent increases with increase of substrates temperatures The current–voltage characteristic of (CuInSeTe/CdS, CuInSSe/CdS and CuInSTe/CdS) heterojunction shows that the (CuInSeTe/CdS) produced at Ts=303 K is the best one

Main Subjects

Physics

No. of Pages

71

Table of Contents

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Language

English

Data Type

Arab Theses

Record ID

BIM-757313