On the electrical and charge conduction properties of thermally evaporated MoO x on n- and p-type crystalline silicon

In this work, the electrical and charge conduction characteristics of a contact structure featuring thermally evaporated MoOx, deposited on n- and p-type crystalline silicon (c-Si), are extensively investigated by room temperature current–voltage (I–V), transmission line measurements (TLM), and temperature-dependent current–voltage measurements (I–V–T). XRD diffraction spectrum shows that the deposited MoOx film exhibits amorphous nature. From TLM measurements, the values of contact resistivity are calculated to be ρc: 55.9 mΩ-cm2 for Ag/MoOx/n-Si and ρc: 48.7 mΩ-cm2 for Ag/MoOx/p-Si. The barrier parameters such as barrier height (ϕe) and ideality factor (n) are investigated by the thermionic emission theory for I–V and I–V–T measurements. The ϕe, n, and conventional Richardson plot demonstrate resolute temperature dependency, obeying the barrier height of Gaussian distribution model. The uniform barrier height values are calculated to be ϕb:1.24 eV for Ag/MoOx/n-Si and ϕb:0.66 eV for Ag/MoOx/p-Si from the extrapolation of ϕe at n= 1 of the linear fitting of the variation with the experimental barrier height ϕe with ideality factor. The activation energy (Ea) and Richardson constant (A*), obtained from Richardson plot, are much smaller than ϕb and the theoretical values of n- and p-type c-Si. The modified Richardson plot yields more reliable Richardson constant and homogeneous barrier height values of 106.2 Acm−2 K−2 and 1.21 eV, 23.4 Acm−2 K−2 and 0.63 eV for Ag/MoOx/n-Si and Ag/MoOx/p-Si heterostructures, respectively. The results demonstrate that thermally evaporated MoOx has particular advantages due to its good rectifying characteristics such as the extra enhancement to barrier height and low contact resistivity for interfacial layer applications. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.