The development of polycrystalline silicon thin film on low cost substrates for solar cells is showing an urgent need to reduce cost. In order to achieve high quality

large grains silicon films

high temperature processes have to be used. So the substrates must be high temperature resistant

and fulfill requirements concerning thermal expansion

chemical and mechanical stability. Up to now

silicon based materials are the best choice to satisfy the requirements mentioned above. In this paper

low cost SSP substrates are chosen for our thin film solar cells. SSP substrates are manufactured by melting silicon powder by Fraunhofer institute of solar energy system

Germany. Two kinds SSP substrates

made from high purity silicon powder and from homemade low purity silicon powder

are used in our experiments. The morphology of SSP substrates were measured by using SEM.It can be seen that either made from high purity silicon powder or from homemade low purity powder has very rough surface. The average grain size is about 50～100μm. AES and ICPAES reveal that there are O

B

Fe

Mn and Cr impurity in the low purity SSP substrates and the concentration of Fe and Cr exceed 10

17

cm

-3

.High purity SSP substrates have 3%～4% oxygen also. The cell's fabrication processes include:substrate treatments; epitaxy of polycrystalline silicon thin film using rapid thermal chemical vapor deposition (RTCVD); emitter formation; front and rear contacts fabricating; anti reflection coating (ARC) deposition. The resistivity characteristics of the epitaxial thin film was 0.1Ω·cm. Hall mobility is 20～70cm

2

/V·s.Film thickness is 20～50μm and average grain size are 50～100μm.The largest growth rate is 5μm/min. The best thin film solar cell's conversion efficiency of 6.36% and 4.5% (AM1.5

25℃

1cm

2

) have been achieved on high and low purity substrate. These results show that low cost thin film solar cells have great potentialities. Although anti reflect coating (ARC) fabrication improves cells' performance obviously (cell's efficiency increases 14%～22% with SiN)

PC1D calculation shows that the best ARC can increase cell's efficiency 40%

that means our cell's ARC is not optimized. Additionally

the cell's efficiencies increases 4%(some results reach 10%～15%) after 30 minutes forming gas annealing in low temperature. That contributes to reduction of contact resistance and partial passivation of grain boundaries and defects. In conclusion

the polycrystalline silicon thin film solar cells on SSP substrates shows a potential way to reduce the cost of solar cells. Further research will be done in our laboratory.