Electret webs include a thermoplastic resin and a charge-enhancing additive. The charge-enhancing additive is a fused aromatic thiourea, a fused aromatic urea compound, or a combination thereof. The change-enhancing additive may also include a hindered amine light stabilizer compound. The electret webs may be a non-woven fibrous web or a film. The electret webs are suitable for use as filter media.