High-efficiency p/n In/sub 0.53/Ga/sub 0.47/As solar cell for tandem applications

InP-based multijunction tandem solar cells show great promise for high conversion efficiency (/spl eta/) and high radiation resistance. InP and its related ternary and quaternary compound semiconductors such InGaAs and InGaAsP offer desirable combinations of energy bandgap values which are very suitable for multijunction tandem solar cell applications. In this work we present results on an InGaAs solar cell with a very high current density 60 mA/cm/sup 2/ (the highest ever reported) with a /spl eta/=10.2% under natural sunlight, an InP solar cell with /spl eta/=13% under natural sunlight without anti-reflection coating, and preliminary results about a tandem InP/InGaAs solar cell. It is shown that a patterned tunnel junction is necessary to allow current matching in the tandem by avoiding photons absorption in the InGaAs tunnel junction.<
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