ITERATIVELY DERIVED OPTICAL-CONSTANTS OF MOO3 POLYCRYSTALLINE THIN-FILMS PREPARED BY CVD

Polycrystalline MoO3 thin films have been prepared by oxidation at hig h temperature of molybdenum compound layers deposited by chemical vapo ur deposition (CVD) from molybdenum hexacarbonyl Mo(CO),. In this pape r is presented the experimental procedure to prepare polycrystalline M oO3 coatings by annealing at various temperatures and in various annea ling environments of ''black molybdenum'' or ''reflective molybdenum'' thin films. From X-ray diffraction measurements the structure of the films has been determined. The optical constants II and k of films wer e calculated by numerical iteration, using the Fresnel laws and disper sion relations of n and k. From these results the optical gap E-g has been deduced. AU the samples exhibited the electrochromic effect. (C) 1997 Elsevier Science S.A.