The influence of chlorine on the optical properties of monoclinic lead phthalocyanine thin films

The optical transmittance and absorption of thin films of monoclinic lead phthalocyanine have been studied as a function of exposure to chlorine and air. The effect of chlorine on the refractive index and dielectric constant of freshly prepared films was estimated from reflectivity data in the photon energy range 2.1–2.6 eV. Responsivity and recovery from gaseous exposure were studied with regard to the applicability of lead phthalocyanine to the fabrication of an optical chlorine sensor.