An investigation of electrical properties of (P-N)‎ junction porous silicon layer

Dissertant

Jawad, Muna Salih Muhammad

Thesis advisor

Ulwan, Ulwan Muhammad

University

University of Technology

Faculty

-

Department

Applied Sciences Department

University Country

Iraq

Degree

Master

Degree Date

2013

English Abstract

p-n porous silicon junction prepared by usingphoto-electrochemicaletching(PEC) for abrupt (p-n) silicon junction, in Hydro Fluoric acid HF of concentration (25%): Ethanol (1:1), using He:Ne laser sourcewith wavelength (632.8)nm as an illumination source with intensity of (10.7)mW/cm2.

The etching current density was about (12)mA/cm2,while the etching time was varied in the range of (3,5,10,15,20,25)min.The etching process was carried out with homemade system from Teflon cell which provide us a porous silicon layer with uniform cross sectional area.

This uniformity well recommended for the application of porous silicon in optoelectronic field.

Increasing of etching time leads to dramatic changes in morphological, optical and electrical properties.

The morphological properties of the etched (p-n) junctionsamples showed a formation of porous silicon layer with two significant regions: micro size silicon region and nano size silicon region with a large number of a small pores and trenches lined in random directions.

The PL measurements show high peak intensity at low etching time especially at (5)min due to the high density of silicon nano structure at the (p-n) junction porous silicon layer and this layer behavior as light emitting porous silicon layer LEPSi.The PL PDF created with pdfFactory trial version www.pdffactory.com measurements showed low peak intensity at high etching time due to the low density of silicon nano structure region.The reduction in the PL intensity is referring to the increase of non- radiative recombination process.

The dark J-V characteristic of short etching time sample shows a rectification behavior with different rectification ratio.

Increasing of etching time to high value showed a non-rectifying behavior in (p-n) junction porous samples.

The value of the photocurrent for (p-n) porous sample at low etching time has very small value compared with the other (p-n) junction porous silicon samples prepared at long etching time and this layer can be used for perpetration of light emitting (p-n) junction porous rather than photo conductive and photovoltaic devices.

The result of the photoluminescence and the photocurrent studies indicate that the (p-n) junction porous can be used for application of efficient light emitting diode and photovoltaic cell.

Main Subjects

Engineering & Technology Sciences (Multidisciplinary)

Topics

• Electrical properties

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-418170