HETEROSTRUCTURE SINGLE CRYSTAL S PHOTOVOLTAIC CELL Type A, Semiconductor Heterojunction Silicon Devices Quarterly Report No. 1, September 27-December 31, 1976

摘要

The present report gives an account of the work that has been done on SnO2/Si Heterostructure solar cells. The report can roughly be divided into two parts. The first part involves characterization and analysis of cells obtained from Emdex Corporation and the second part deals with fabrication and analysis of cells made at Exxon.nIn the Emdex/Innotech cells, a major portion of current losses are due to reflection and shadowing effects due to grids. The SnO2- thin films act as an antireflection coating but is not comparable in performance to those used in commercial p/n junction solar cells. The shape of the spectral response curve was theoretically calculated by taking into account the reflection losses. In most cases it is not necessary to assume an inversion layer at the surface to account for the decrease in spectral response at short wavelengths. Further for these cells we did not observe photocurrent suppression as suggested in some earlier published work by others. The diode factor, the reverse saturation current, series and shunt resistances were determined for these cells. The diode factor n determined from dark and light I-V are not the same as one would expect from a normal solar cell. The first batch of newly fabricated SnO2 /Si cells show low efficiency. The problems with these cells and ways to improve its performance are discussed.