Current Noise in Thermistor Bolometer Flakes

The characteristics of the additional electrical noise generated by iron oxide thermistor bolometer flakes due to direct current passing through the units is investigated. It is found that the noise is similar to the current noise observed in other semiconductors. The current noise power density is observed to depend inversely upon frequency, to be approximately proportional to the direct current, and to be independent of temperature. It is indicated that the major source of the noise is at the electrodes which make electrical contact to the semiconductor. Electrodes produced by evaporated gold applied through a potential difference are found to yield relatively low noise flakes.