Characterization of amorphous silicon for low cost MIS solar cells

Theoretical considerations indicate that as compared to other possible structures, the MIS structures are best suited for solar cells on non-crystalline semiconductors. In our preliminary experiments, we have fabricated MIS diodes on e-beam deposited a-Si using thermal evaporation of top metal layer. The I-V characteristics of Cr-Cu-Cr/a-Si diodes were measured as a function of temperature in the range of 200-400°K. Also, at room temperature, the high frequency C-V and G-ω characteristics were measured. The analysis of the experimental data suggests that the current conduction in these devices is space charge limited, with the carriers hopping between the space charge "pockets".