Unveiling the evolution of microstructural and optoelectronic properties of spray‐pyrolyzed <scp>ZnO</scp> thin films via tailoring the aerosol deposition time

Abstract ZnO thin films with diverse thicknesses were deposited via the spray pyrolysis technique by varying the deposition time ( τ ). The XRD analysis shows an increase in polycrystallinity for films with an increase in τ ; however, all films exhibit predominant growth along the c ‐axis [002] direction. The FE‐SEM analysis shows the growth of well‐aligned ZnO nanorods upright on the substrate at τ = 20 min. EDS analysis confirms the high quality ZnO film formation with a slightly rich oxygen concentration. The films exhibit optical transmittance &gt;90%, with the highest of 95% when deposited for 24 min. There is a rise in crystallite size along with film thickness; however, bandgap energy ( E g ) declines with a rise in τ . The inverse relation of E g with Urbach energy ( E u ) is attributed to superior crystallinity at lower E u . Under optimal deposition time τ = 20 min, the film shows the highest dark conductivity 108.2 S/cm, free electron concentration η = 3.76 × 10 19 /cm 3 , and mobility μ = 17.98 cm 2 V −1 s −1 . For τ = 20 min, the film exhibits the best figure of merit, Φ TC‐H = 2.03 × 10 −3 Ω −1 , Φ TC‐H‐HR = 4.11 × 10 −2 Ω −1/12 , and the least sheet resistance, R s = 275 Ω/□.