The electrical properties of nitrogen‐containing amorphous hydrogenated carbon layers are investigated. The nitrogen concentration was between 0 and 6 at%. The electrical conductivity is found to increase with the nitrogen content. The temperature dependent conductivity in the temperature range between 150 and 350 K can be well fitted by a semi‐empirically derived equation which considers the conductivity as a superposition of two hopping mechanisms with different activation energies. Together with experimental results on the optical properties and the mass density, these data allowed to propose a structural model which explains the observed effects in terms of familiar a‐C:H cluster models.
A flexible numerical procedure for the calculation of thin-film optical constants from specular transmittance and reflectance data is presented. The method is based on the minimization of a quadratic error function, which may be adapted to the specifics of the optical behaviour of the given sample (or set of samples), and the given wavenumber region. The flexibility in choosing an appropriate form of the minimized error function, in combination with the powerful minimization method of conjugated gradients, allowed us to investigate the optical constants of very different types of novel thin-film material with a complicated optical loss behaviour. In particular, the results concerning the investigation of single- and two-layer systems based on the following technologically interesting optical thin film materials are presented: (1) amorphous silicon as an example of-an anorganic solar cell material; (2) as-deposited (rough) CVD diamond layers as an example of a polycrystalline protective material; (3) hydrogenated amorphous carbon, applicable as a protective long-wavelength in antireflection coating as well as a spectrally selective solar absorber; (4) copper phthalocyanine layers as an example of a molecular solid, potentially applicable as an organic solar cell material; (5) rare-earth diphthalocyanine layers, interesting because of their electrochromic behaviour.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.