Bazaka, KaterynaJacob, Mohan V.2025-06-112025-06-11http://www.scopus.com/inward/record.url?scp=85009736213&partnerID=8YFLogxKhttps://hdl.handle.net/1885/733758858Owing to their amorphous, highly cross-liked nature, most plasma polymers display dielectric properties. This study investigates iodine doping as the means to tune optoelectronic properties of plasma polymer derived from a low-cost, renewable resource, i.e., Melaleuca alternifolia oil. In situ exposure of polyterpenol to vapors of electron-accepting dopant reduced the optical band gap to 1.5 eV and increased the conductivity from 5.05 × 10-8 S/cm to 1.20 × 10-6 S/cm. The increased conductivity may, in part, be attributed to the formation of charge-transfer complexes between the polymer chain and halogen, which act as a cation and anion, respectively. Higher levels of doping notably increased the refractive index, from 1.54 to 1.70 (at 500 nm), and significantly reduced the transparency of films.K.B. is grateful to the funding received from ARC DECRA (DE130101550)enPublisher Copyright: © 2017 by the authors; licensee MDPI, Basel, Switzerland.Iodine dopingOptical propertiesOrganic polymerPlasma polymerizationThin film2017-01-0110.3390/nano701001185009736213