An evaluation of potentially low-cost silicon substrates for metal-insulator-semiconductor solar cells

Cr metal-insulator-semiconductor solar cells were fabricated on special silicon substrates identified as 5-in.-diam Czochralski wafers, Wacker polycrystalline-Si, silicon on ceramic, and IBM ribbon. These cells produced open circuit voltages ranging from 0.58 to 0.48 V, short circuit current density from 32 to 18 mA/cm², and efficiency from 11.5 to 5.1% depending on surface perfection and diffusion length. Spectral response data gave diffusion length values in a range from 150 to 39 mm. Calculations showed interface state density values ranging from 4.2×10¹² to 1.2×10 ¹³/cm² eV, which are quite high due to the surface nature of these substrates.