Study and development of new solar cells

Dissertant

al-Nasir, Qusayy Asim Hanna

Thesis advisor

Hulw, Hasan W.
al-Hasimi, Abbas F.

University

University of Technology

Faculty

-

Department

Department of Electrical Engineering

University Country

Iraq

Degree

Ph.D.

Degree Date

2010

English Abstract

Photovoltaic are the promising renewable technology for the 21st century.

Three generations of solar cell technologies are established in the previous century.

This work involves an extensive analysis of the selection of optimum band-gap (Eg) of ternary III-V compounds for application in the third generation (3G) multi-junction solar cells.

Several (3 and 4 junctions) structures have been realized with different layer material compositions for simulating the performance of III-V multi-junction solar cells.

The highest efficiency can be achieved if two parameters are satisfied: Lattice matching and current matching of the different layers of the solar cell.

Those parameters are critically dependent on (Eg).

A special program is designed and implemented in Visual Basic language to select the band-gap of each composition through variation of its component’s concentrations which is an important tool to make the design process more efficient, otherwise it would be almost impossible to achieve the design.

A new five groups of ternary III-V materials are established to reach the optimum values of (Eg) that satisfy the lattice and current matching.

It is found that group (D) is the best, which has the band-gap division of (0.97bottom / 1.52middile / 2.07top) with structures) Ga0.64In0.36As / Ga0.27In0.73P / Al0.68In0.32As) and (GaAs0.70Sb0.30 / Ga0.27In0.73P Al0.68In0.32As) having the optimum lattice and current matching.

The Back Surface Field (BSF) is used in the (1G) and (2G) generation solar cells.

This technique increases the average minority carrier lifetime.

In this work new experimental conditions for increasing the average minority carrier lifetime are found.

This enhanced the solar cell efficiency.

Different annealing temperatures (620-940) ℃ and different annealing times (60-180) sec.

are used.

A thin layer of aluminum (Al) is passivity on the back surface of the crystalline silicon (c-Si) substrate.

The longest average minority carrier lifetime obtained is (5.455μs) using microwave photoconductive decay (μ-PCD) technique at annealing temperate of (700 ˚C) and annealing time of (150 sec) in order to decrease Surface Recombination Velocity (SRV).

Main Subjects

Electronic engineering

Topics

• Solar cells

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305328