Several Mn2+ centers observed by EPR in sol–gel ZnO films. Mn2+ ions localized at Zn2+ sites in ZnO grains and disordered ZnO phase. Sixfold coordinated Mn2+ ions localized in inter-grain region. Aggregated Mn in insular-like regions between ZnO grains in the ZnO:5%Mn film. Aggregated Mn phase presence and distribution observed by EPR and EDX-STEM.