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.