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InGaP/GaAs‐based multijunction solar cells
Author(s) -
Takamoto Tatsuya,
Kaneiwa Minoru,
Imaizumi Mitsuru,
Yamaguchi Masafumi
Publication year - 2005
Publication title -
progress in photovoltaics: research and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.286
H-Index - 131
eISSN - 1099-159X
pISSN - 1062-7995
DOI - 10.1002/pip.642
Subject(s) - optoelectronics , materials science , solar cell , suns in alchemy , energy conversion efficiency , equivalent series resistance , gallium arsenide , indium , electrical engineering , voltage , engineering
The conversion efficiency of InGaP/(In)GaAs/Ge ‐based multijunction solar cells has been improved up to 29–30% (AM0) and 31–32% (AM1·5G) by technologies, such as double‐hetero wide band‐gap tunnel junctions, combination with Ge bottom cell with the InGaP first hetero‐growth layer, and precise lattice‐matching to Ge substrate by adding 1% indium to the conventional GaAs lattice‐match structure. Employing a 1·95 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 and cell size have been designed for concentrator applications in order to reduce the energy loss due to series resistance, and 38% (AM1·5G, 100–500 suns) efficiency has been demonstrated. Furthermore, thin‐film structure which is InGaP/GaAs dual junction cell on metal film has been newly developed. The thin‐film cell demonstrated high flexibility, lightweight, high efficiency of over 25% (AM0) and high radiation resistance. Copyright © 2005 John Wiley & Sons, Ltd.