Title :
Paper-Thin InGaP/ GaAs Solar Cells
Author :
Takamoto, Tatsuya ; Kodama, Tomoya ; Yamaguchi, Hiroshi ; Agui, Takaaki ; Takahashi, Naoki ; Washio, Hidetoshi ; Hisamatsu, Tadashi ; Kaneiwa, Minoru ; Okamoto, Kohji ; Imaizumi, Mitsuru ; Kibe, Koichi
Author_Institution :
Solar Syst. Dev. Center, Sharp Corp., Nara
Abstract :
A paper-thin, lightweight InGaP/GaAs solar cell with high efficiency and flexibility has been developed. A high-efficiency thin-film cell can be obtained for cell fabrication both before and after removing the substrate. Introducing a tunnel junction as the contact layer between the cell and metal film improves cell characteristics (Fill Factor (FF) and open-circuit voltage (Voc)). A highly doped n-type layer is necessary for good ohmic contact at the metal film interface. High radiation resistance of a thin-film cell was confirmed for a GaAs cell with a one-micron base layer. The thin-film cell was laminated for better handling. The laminated cell efficiency was about 22%. Anti-reflective coating is necessary on the laminate film to improve cell efficiency. A prototype unit panel using the laminated cells was developed for space application. An output power per weight of over 1W/g is possible for the unit panel. However, development of a bypass diode with thin-film structure is currently a problem, and reliability tests need to be performed for the unit panel
Keywords :
III-V semiconductors; antireflection coatings; gallium arsenide; metallic thin films; ohmic contacts; semiconductor device reliability; semiconductor thin films; solar cells; thin film devices; InGaP-GaAs; antireflective coating; bypass diode; doped n-type layer; flexibility; high radiation resistance; laminated cell efficiency; metal film; ohmic contact; open-circuit voltage; reliability tests; thin lightweight solar cells; tunnel junction; Coatings; Fabrication; Gallium arsenide; Laminates; Ohmic contacts; Photovoltaic cells; Prototypes; Substrates; Transistors; Voltage;
Conference_Titel :
Photovoltaic Energy Conversion, Conference Record of the 2006 IEEE 4th World Conference on
Conference_Location :
Waikoloa, HI
Print_ISBN :
1-4244-0017-1
Electronic_ISBN :
1-4244-0017-1
DOI :
10.1109/WCPEC.2006.279833
