A pn junction solar cell of area 1.0 cm² illuminated uniformly with 100 mW cm⁻², has the following parameters: Efficiency = 15% open circuit voltage = 0.7 V fill factor = 0.8, and thickness = 200 µm. The charge of an electron is 1.6×10⁻¹⁹ C. The average optical generation rate (in cm⁻³s⁻¹) is