The precipitation-spin coating technique is employed to prepare nanostructure ZnO quantum dot (QD) films at different thicknesses. The X-ray diffraction analysis reveals the polycrystalline thin film growth along (101) plane and crystallinity improvement with thickness rise. The increase in thickness causes an increase (5.14 - 7.73 nm) and a decrease (3.39- 3.22 eV) in grain size and bandgap respectively. At optimized thickness, the ZnO QD thin film exhibits 72 % transmittance with the lowest resistivity of 16.24 x 10-2 Ωcm and highest carrier mobility of 15.38 cm2/Vs rendering it viable for potential utilization as an electron transport layer for perovskite devices.