Temperature-dependent transport properties of CVD-fabricated n-GaN nanorods/p-Si heterojunction devices.

We report on the structural, electrical, and transport properties of high quality CVD-fabricated n-GaN nanorods (NRs)/p-Si heterojunction diodes. The X-ray diffraction (XRD) studies reveal the growth of hexagonal wurtzite GaN structure. The current-voltage ( I - V ) characteristics of the n-GaN NRs/p-Si heterojunction were measured in the temperature range of 300-475 K. The ideality factor ( n ) and zero-bias barrier height ( ϕ B0 ) are found to be strongly temperature-dependent. The calculated values of ϕ B0 are 0.95 and 0.99 eV according to Gaussian distributions (GD) and modified Richardson for GD, respectively, which are in good agreement with the band offset of GaN/Si (0.95 eV). A Richardson constant of 37 cm -2 K -2 was obtained from the modified Richardson plot, which is close to the theoretical value for p-Si (32 cm -2 K -2 ). The Gaussian distributions (GD) of inhomogeneous barrier height (BHs) and modified Richardson for GD of BHs with TE have also been used to explain the obtained transport properties.