HETEROJUNCTIONS OF SOLID C70 AND CRYSTALLINE SILICON - RECTIFYING PROPERTIES AND BARRIER HEIGHTS

Heterojunctions of solid C70 and n- or p-type crystalline Si have been made. Current-voltage measurements show that both C70/n-Si and C70/p-Si contacts are rectifying but their directions of rectification are opposite to each other. Thermal activation measurements at a fixed forward bias show an exponential dependence of current on the reciprocal of temperature, from which we determine the effective barrier height as 0.23 eV for C70/n-Si and 0.27 eV for C70/p-Si. Relative dielectric constant of solid C70 was determined to be 4.96 through the study of high-frequency capacitance-voltage characteristics for Ti/C70/p-Si structures. (C) 1995 American Institute of Physics.