Recent improvements in AMOS solar cells

Several improvements in AMOS cell fabrication processes have been developed. These improvements consist of a new chemical surface preparation, a new form of oxide layer and a better antireflecting coating. It was found that AMOS cells with the chemical surface treatment NHH (NH4OH: H2O2:H2O = 1:1:10) and SHH (H2SO4:H2O2:H2O = 10:1:1), prior to oxidation, yield a lower reverse saturation current, higher open-circuit voltage, near-unity diode ideality factor and a higher degree of consistency. The performance of AMOS cells made by physically-deposited oxide layers is comparable, if not superior, with that of water-vapor grown oxide cells. The thermal degradation of open-circuit voltage in AMOS cells with the improved technology is also less pronounced. The application of antireflection coatings has been improved by the use of laser flash evaporation so as to eliminate the previously observed degradation in open-circuit voltage.