Effect of laser irradiation on characteristics of porous silicon photodetector

Dissertant

Abbud, Marwah Qasim

Thesis advisor

Ismail, Raid A.

University

University of Technology

Faculty

-

Department

Applied Sciences Department

University Country

Iraq

Degree

Master

Degree Date

2012

English Abstract

In this project, a double junction Al/PSi/Si/Al is presented.

The Porous silicon (PSi) layer was prepared by electrochemical etching using different etching current densities.

The effect of Nd-Yag laser irradiation on the Morphological, structural, electrical and optoelectrical properties of Al/PSi/Si/Al photodetector are demonstrated.

The morphological investigation, carried out using AFM, showed that the root mean square roughness is increased after laser irradiation.

XRD results revealed that the laser irradiation leads to a change in the preferred orientation to (100) plane and the FWHM increased with increasing the laser fluence.

I-V characteristics confirmed that laser irradiation of porous Si improves the junction characteristics, the ideality factor and the rectification ratio results support this improvement.

The best junction characteristics (ideality factor, rectification ratio) were obtained for photodetector made using (10mA/cm2) current density and irradiation fluence of (60mJ/cm2).

The spectral responsivity of photodetectors is increased after laser irradiation.

Maximum responsivity of (0.5A/W) at λ=825nm was obtained for photodetectors prepared using 20mA/cm2 and treated with laser fluence of (40mJ/cm2).

No shift in peak responsivity was observed after laser irradiation.

The figures of merit of the fabricated photodetectors are calculated before and after laser irradiation.

Photodetector prepared using 20mA/cm2 etching current density and laser irradiated fluence of (40mJ/cm2) gave a detectivity (D) of (4.3*1010w-1cm HZ1/2) at λ=825nm.

Minority carrier lifetime measured showed strong dependence on etching current density and laser fluence.

Main Subjects

Physics

Topics

• Silicon
• Semiconductors
• Lasers

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-419748