Sol-gel derived thin films of Zn0.95Mn0.05O have been implanted with Ar9+ ions with doses viz. 5x10e14 ions/cm2 (low), 1x10e15 ions/cm2 (intermediate) and 1x10e16 ions/cm2 (high). Structural, morphological, optical and magnetic properties of the films have been investigated. Structural study confirmed single phase, wurtzite structure of the films. The absence of impurity phase has been confirmed from several measurements. Ion implantation induces a large concentration of point defects into the films as identified from optical study. All films exhibit well above room temperature (RT) intrinsic ferromagnetism (FM) as evidenced from field and temperature dependent magnetization measurements. The magnetization attains the maximum value for high dose of Ar9+ ion implanted film. It shows RT saturation magnetization (MS) value of 0.69emu/gm. The observed FM has been correlated with proportion of intrinsic defects, such as, zinc and oxygen vacancies and the values of MS. Defect induced formation of bound magnetic polaron actually controls the FM. The utility of these films in transparent spin electronic device has also been exhibited.