Studies of sputtered CdTe and CdSe solar cells

CdTe has recently become the most commercially successful polycrystalline thin filmsolar module material. Its low cost, large-area solar module is reshaping the silicondominatedsolar panel market; however, CdTe has much room to improve and thus morefundamental understanding is needed. Current thin film solar cell research is focused ontwo areas: One is identifying loss mechanisms and understanding the polycrystallinenature of single junction device to improve device performance. Another is searching fornew materials and fabricating tandem solar cells. In this study, along with other people’swork to improve the efficiency of CdTe solar module, I studied loss mechanism andgrowth mode of CdTe solar cells to have fundamental understanding of polycrystallinefilms. In addition to that, in an effort to make tandem solar cells, I fabricated andcharacterized CdSe solar cells, which is considered as an ideal candidate for the top cellwith its band gap of 1.7 eV.This dissertation is designed to show similarities and differences between CdTeand CdSe solar cells, side by side. After the introduction (Chapter1), I will review thephysical properties of CdTe and CdSe solar cells (Chapter 2). Two primary tools to study defects and surface morphology were photoluminescence (PL) and atomic forcemicroscopy (AFM). PL showed information on the crystallinity and defects of CdTe andCdSe films before and after annealing.(Chapter 3). AFM measurements and their analysisusing scaling theory revealed information on the growth modes of CdTe and CdSefilms.(Chapter 4).With the goal of exploring suitability for tandem structures with ~1.7 eV top celland ~1.1 eV bottom cell, I fabricated and characterized single-junction CdSe devices.(Chapter 5) In addition, for the bottom cell I fabricated HgCdTe cells with Eg~1.1 eV.Single junction HgCdTe and two-terminal CdTe/HgCdTe tandem solar cells werefabricated and characterized. (Chapter 5)

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Physics

Grantor dc:publisher

University of Toledo

Year dc:date

2012

Author dc:creator

• Kwon, Dohyoung

Contributors dc:contributor

• Compaan, Alvin

• Physics
• CdTe
• CdSe
• solar cell
• photovoltaic
• AFM
• scaling
• PL
• photoluminescence

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=toledo1345260902

OAI identifier oai:identifier

oai:etd.ohiolink.edu:toledo1345260902