p +/n/n + InP solar cells directly on Si substrates

p +/n/n+ InP solar cells have been fabricated directly on (100) Si substrates by low-pressure organometallic vapor phase epitaxy. The best experimental cell without an antireflection coating exhibits an air mass one efficiency of 11.9%. The corresponding open-circuit voltage, short-circuit current, and fill factor are 0.78 V, 22.47 mA/cm2, and 0.63, respectively. An electrical characterization identifying loss mechanism is proposed.