Beneficial effects of sodium on CuIn1-XGaXS2 thin film solar cells

Author

Kaul, Ashwani ; Vasekar, Parag ; Dhere, Neelkanth G. ; Moutinho, Helio

Author_Institution

Florida Solar Energy Center, Cocoa, FL, USA

fYear

2009

fDate

7-12 June 2009

Abstract

Chalcopyrites are important contenders among solar cell technologies due to their direct band gaps and high absorption coefficients. Copper indium gallium sulfide, CuIn_1-xGa_xS₂ (CIGS2) thin films have been grown by sulfurization with copper rich compositions. However, the desired free carrier concentration range of 10¹⁶-10¹⁷/cm³ can be achieved fairly easily with copper deficient compositions avoiding the toxic etching process. Due to the unavailability of cuprous sulfide which acts as a fluxing agent in copper rich films and is responsible for better film morphology, it is difficult to produce device quality films in copper deficient compositions. The effects of sodium addition on the film microstructure and the device performance are being studied.

Keywords

carrier density; copper compounds; gallium compounds; indium compounds; semiconductor thin films; sodium; solar cells; ternary semiconductors; thin film devices; CuIn_1-xGa_xS₂-Na; chalcopyrites; film morphology; free carrier concentration; microstructure; solar cells; sulfurization; thin films; Absorption; Copper; Etching; Gallium compounds; Indium; Microstructure; Morphology; Photonic band gap; Photovoltaic cells; Transistors;

fLanguage

English

Publisher

ieee

Conference_Titel

Photovoltaic Specialists Conference (PVSC), 2009 34th IEEE

Conference_Location

Philadelphia, PA

ISSN

0160-8371

Print_ISBN

978-1-4244-2949-3

Electronic_ISBN

0160-8371

Type

conf

DOI

10.1109/PVSC.2009.5411211

Filename

5411211