Title :
Multijunction solar cell technologies - high efficiency, radiation resistance, and concentrator applications
Author :
Takamoto, Tatsuya ; Agui, Takaaki ; Kamimura, Kazutaka ; Kaneiwa, M.
Author_Institution :
Sharp Corp., Nara, Japan
Abstract :
The conversion efficiency of InGaP/(In)GaAs/Ge-based multijunction solar cells has been improved up to 29-30% (AM0) and 31-32% (AM1.5 G) by technologies, such as double-hetero wide band-gap tunnel junctions, combination with Ge bottom cell with the InGaP first layer, and precise lattice-matching to Ge substrate by adding 1% indium to the conventional GaAs lattice-match structure. Employing a 1.96 eV AlInGaP top cell should improve efficiency further. For space use, radiation resistance has been improved by technologies such as introducing of an electric field in the base layer of the lowest-resistance middle cell, and EOL current matching of sub-cells to the highest-resistance top cell. A grid structure has been designed for concentrator applications in order to reduce the energy loss due to series resistance, and 36% (AM1.5 G, 100-500 suns) efficiency has been demonstrated.
Keywords :
III-V semiconductors; aerospace instrumentation; gallium compounds; indium compounds; radiation hardening (electronics); semiconductor junctions; solar absorber-convertors; solar cells; tunnelling; 29 to 30 percent; 31 to 32 percent; Ge; InGaP-(In)GaAs; concentrator application; conversion efficiency; double-hetero wide band-gap tunnel junction; energy loss; grid structure; lattice-matching; multijunction solar cell technologies; radiation resistance; space application;
Conference_Titel :
Photovoltaic Energy Conversion, 2003. Proceedings of 3rd World Conference on
Print_ISBN :
4-9901816-0-3
