On the high curvature coefficient rectifying behavior of nanocrystalline diamond heterojunctions to 4H-SiC.

Heterojunctions of p⁺ B-doped nanocrystalline diamond (NCD) to n^- 4H-SiC were studied by electrical and cathodoluminescence (CL) methods. Current rectification at 30 °C had a curvature coefficient γ₀ of 42.1 V^-1 at zero bias, γ_max of 105.35 V^-1 at 0.2 V, and a reverse current of <10 nA/cm². The NCD sheet resistance decreased from 4.1×10¹¹ to 403.56 Ω/sq. as the carrier density N_s was increased from 3.5×10⁵ to 1.5×10¹⁶ cm^-2 by B₂H₆ doping. The 348 cm²/V-s mobility of the B-free NCD films was comparable to that of single crystal diamond. CL data revealed traps 0.6-0.8 eV from the NCD E_V edge. [ABSTRACT FROM AUTHOR]