Screen printed SIS-type solar cells

Experimentation was performed on the formation of an SIS junction on n-type monocrystalling Si wafers using thick film techniques and an indium-tin oxide thick film paste. A SiO layer 20 A thick grew on the optically smooth side of monocrystalline wafers during the firing of a screen printed Au back contact. An ITO film 2000 A thick was grown on the oxidized surface and a silver front thick-film grid was fired on the other side. Various firing temperatures were examined to test the effects on the open circuit voltage and the current density. The best samples displayed an open circuit voltage of 293 mV for an illumination of 55-90 mW/sq cm, after which the short circuit current fell off. The best cell efficiencies were less than one, although the performance degraded less than 10 pct in 6 mos.