The authors report an enhanced infrared spectral response of GaAs-based solar cells that incorporate type II GaSb quantum dots ͑QDs͒ formed using interfacial misfit array growth mode. The material and devices, grown by molecular beam epitaxy, are characterized by current-voltage and spectral response characteristics. From 0.9 to 1.36 m, these solar cells show significantly more infrared response compared to reference GaAs cells and previously reported InAs QD solar cells. The short circuit current density and open circuit voltages of solar cells with and without dots measured under identical conditions are 1.29 mA/ cm 2 , 0.37 V and 1.17 mA/ cm 2 , 0.6 V, respectively.