Photovoltaic effect and photoconductivity in triode-sputtered thin-films of Hgl-XCdXTe
Lopez, Jorge Luis
Wilson, William L.
Master of Science
A study was made of trîode sputtered thin films of Hg. Cd Te to determine their physical, electronic, and electrooptic characteristics. The films were sputtered from inhomogeneous targets made from HgTe enriched Hg CdTe onto glass substrates. The composition of the films was determined by electron microprobe. Electrical characteristics were determined by resistivity and Hall data, and electrooptic response by exposure to a black body source through a grating monochrometer. The films exhibited photoconductivity and photovoltaic response in the range from at least 2-1 g. The photovoltage was believed to be due to a graded-gap mechanism induced by a lateral compositional gradient. The frequency response of the detectors to a modulated input signal was found to cut off above 3.5 Hz for the photoconductivity and beyond 44 Hz for the photovoltaic effect. The difference is attributed to different lifetimes for electrons and holes. Best D (5,6) for the photoconductivity was 1 , and watts for the photovoltaic effect.