Optical properties of chemical vapor deposited black molybdenum thin films

Thesis/Dissertation · Sat Jan 01 00:00:00 EST 1983

OSTI ID:6980794

Chain, E E

A study of black molybdemun, a new cermet consisting of small Mo particles embedded in MoO/sub 2/ is described. As with most two-phase materials, the optical properties of black molybdenum are significantly different from those of either constituent, and can be adjusted within wide limits through modifications of composition and microstructure due to variations of the fabrication process parameters. Theoretical interpretation of the optical properties of two-phase materials has in the past been hampered by insufficient microstructural characterization. Recent theoretical work by others has lifted the requirements of detailed microstructural knowledge, leaving only two required parameters for characterization of cermet reflectance: the optical properties of the constituent phases and their volume fractions in the cermet. Better characterization is obtained when structural considerations, such as film topology, surface texture and the presence of a possible amorphous phase are taken into account. This approach was adopted to the study of black molybdenum, and accomplished satisfactory agreement between theoretical and observed reflectances. Black molybdenum films were prepared using two separate chemical vapor deposition (CVD) techniques, involving deposition from either Mo(CO)/sub 6/ or MoO/sub 2/Cl/sub 2/. It was found that the influence of composition through a comparison of films with different Mo:MoO/sub 2/ ratios, while the influence of structure on film reflectance was determined by comparing films from these two deposition techniques. During this investigation, black molybdenum films were produced which display a spectrally selective profile--low visible reflectance combined with high infrared reflectance, and which may be applied to photothermal solar energy conversion.

• OSTI ID: 6980794
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
MOLYBDENUM
OPTICAL PROPERTIES
MOLYBDENUM OXIDES
SOLAR CELLS
CERMETS
CHEMICAL VAPOR DEPOSITION
THERMOPHOTOVOLTAIC CONVERTERS
THIN FILMS
CHALCOGENIDES
CHEMICAL COATING
COMPOSITE MATERIALS
DEPOSITION
DIRECT ENERGY CONVERTERS
ELEMENTS
EQUIPMENT
FILMS
MATERIALS
METALS
MOLYBDENUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
SOLAR EQUIPMENT
SURFACE COATING
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
140501* - Solar Energy Conversion- Photovoltaic Conversion