In this study, the electrical performance of atomic layer deposited (ALD) Y₂O₃ films using yttrium tris(di-isopropylformamidinate) [Y(DPfAMD)₃] and yttrium tris(di-tertbutyl-formamidinate) [Y(DBfAMD)₃] as precursors are characterised to verify the suitability of Y₂O₃ as high-k dielectric as well as surface passivation layer in thin-film devices. The films derived from the optimized ALD processes are uniform and smooth with a root-mean-square (RMS) roughness of R_q [Y(DBfAMD)3_] = 0.28 nm and R_q [Y(DPfAMD)3_] = 0.48 nm, respectively. The permittivity, interface trap density and breakdown voltages were determined using a metal-insulator semiconductor (MIS) capacitor. A permittivity of 13.9 (12.3), breakdown voltages of 5 MV cm^-1 (4 MVcm^-1) and low leakage current densities ~10^-7 A cm^-1 at 2 MV cm^-1 were determined for films using the optimized ALD process with [Y(DPfAMD)₃] ([Y(DBfAMD)₃]). Finally, solution processed metal-oxide thin-film transistors (MOTFTs) were passivated by a 4 nm thick Y₂O₃ film in order to study the impact of the surface passivation on the electrical performance of the TFTs under ambient conditions. The Y₂O₃ encapsulation improved the performance by substantially reducing the hysteresis of the transistor characteristic, compared to a non-passivated reference sample. While the integration of the [Y(DPfAMD)₃] based ALD process initiates a significant negative onset voltage shift (V_on = 30 V), the integration of the [Y(DBfAMD)₃] based ALD process results in an onset voltage close to zero.