An Al p -silicon MOS photovoltaic cell

An MOS photovoltaic diode, consisting of Al on p-type silicon with a thin interfacial layer of SiO2, has been found to have good conversion efficiency for solar radiation. Measurements of capacitance versus voltage, current versus voltage, and photocurrent per absorbed photon indicate a most probable surface barrier height of 0.85 eV, approximately twice as large as that for the normal Al p-type silicon diode. A single-layer antireflection coating of silicon monoxide or zinc sulfide was found to increase the short-circuit current by approximately 50%. Double-layer coatings of zinc sulfide over silicon monoxide gave nearly the same increase with a shift of the maximum diode response to the near infrared. Absolute light-conversion efficiencies of 8% at one sunlight level were obtained with short-circuit current densities as high as 26.5 mA/cm2.