Performance of GaAs/Mirror/Cu-Substrate Thin-Film Solar Cells

This paper presents the thermal effect on the performance of a GaAs thin-film solar cell with a 50-200- μm-thick copper (Cu) substrate. The GaAs thin-film solar cell is fabricated by transferring a GaAs solar cell on a Cu substrate with a AuGe/Au mirror. The thin-film solar cells with sufficiently thick Cu substrates exhibit significant performance stability (e.g., V_oc, J_sc, and FF) as the temperature increases. This stability can be attributed to the following two factors: 1) The highly reflective AuGe/Au mirror enhances the light absorption of the thin-film cell with a thin base layer, and 2) the good thermal dissipation of the Cu substrate reduces thermal degradation.