Ultrafast response and high sensitivity semiconductor thermocouple

Abstract

The thermocouple consists of an internal wire (Pt, Au, Ag) inside a glass tube that is pulled down to a diameter of 1-2 /spl mu/m or less. Probes are available with second electrode (leg) from film semiconductor evaporated on the outside of the glass tube. Semiconductor PbTe doping special impurity, provides constant high multitude of the thermoelectric power in the wide temperature interval (-100-200/spl deg/C). Sensitivity of the thermocouple is from 2000 to 300 /spl mu/V/K and does not change for a long time. Special protection on the base of the ultrathin polymer layer permits use of the thermocouple in an aggressive atmosphere. Calculations indicate the response time of the thermocouple is 1 /spl mu/sec. The suitability of this thermocouple for light intensity measurements with micrometer spatial resolution is demonstrated by measuring the focused beam of the laser. In addition, such thermocouples are intrinsically suitable for applications in scanned probe microscopies. All these unique advantages make the pipette thermocouples a new and extremely promising sensor in a variety of applications including microelectronics, microbiology and others.