Pilot line production of high-efficiency GaAs solar cells

Batches of GaAs solar cells with efficiencies exceeding 20% (one sun, AM0) have been fabricated in a recently established pilot line facility. These 2*2-cm/sup 2/ cells are grown in a multiwafer organometallic vapor phase epitaxy (OMVPE) reactor which has demonstrated good uniformity both from run to run and within a single run. The current-voltage characteristics of a typical cell include an open-circuit voltage of 1.05 V, a short-circuit current density of 32.7 mA/cm/sup 2/, and a fill factor of 0.84, resulting in an overall efficiency of 21.2%. A few cells show efficiencies as high as 22.0%. A study of the 34 cells which reached testing from the most recent lot shows that 92% of the cells have efficiencies of 20% or more.<
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