The main objective of this study is to investigate the passivation potential of transition metal oxides (TMO), which are being used as carrier-selective contacts for silicon heterojunction solar cell applications. V₂O_x thin films were deposited on commercial n-type c-Si (111) Cz wafers and corning (Eagle XG) glass substrates using thermal evaporation at a pressure of 5×10^-5 mbar. These films were analyzed to study their electrical, optical, and structural characteristics using temperature-dependent conductivity, minority carrier lifetime, minority carrier lifetime mapping, IV characteristics, UV-Vis analysis, XRD, XRR, XPS, Raman, and AFM. The results showed that the as-deposited films are amorphous and have a high optical transmittance (≈ 80 %) in the visible range. The minority carrier lifetimes by as-deposited V₂O_x thin films ranged from 64 to 294 µs with an increase in film thickness from 1.5 to 10 nm, indicating good surface passivation. In our model, H-terminated silicon undergoes partial oxidation by the first TMO monolayers, leaving oxygen-deficient species in the bulk. A sub-stoichiometric SiO_x interlayer may be produced by interactions between silicon and oxygen. We postulate that the fixed charges acquired by the silicon sub-oxide layers create the field-effect passivation. A 10 nm-thick V₂O_x film is found to have the best optoelectronic properties, including a minority lifetime of 294 µs, an electron concentration of 8.17×10¹⁴ cm^-3, mobility of 5.3 cm²/V-s, and an optical band gap of 2.0 eV. These findings demonstrate that a respectable high implied V_oc of 652 mV can be obtained with only field-effect passivation. We expect substantial improvement in V_oc with post-deposition hydrogen treatment. These results will have significant implications for the fabrication process of silicon heterojunction solar cells.