THE SEEBECK EFFECT IN HIGHLY CONDUCTIVE MU-C-GE-H FILMS AND ITS APPLICATION TO SENSORS

Through investigation, it has been found that a highly conductive microcrystalline Ge:H (mu-c-Ge:H) film generates a large amount of thermoelectric power (maximum -420-mu-V/K). Using this mu-c-Ge:H film thermopile, an optical power sensor and thermal vacuum gauge have been developed. In particular, when this mu-c-Ge:H thermopile is used together with a low-reflectance Ni-P optical absorber, a high-accuracy quick-response laser-beam power sensor with the following characteristics can be realized: (1) responsivity, 0.3 mV/mW; (2) response time, 1.8 s; (3) wavelength range, 0.4 to 1.8-mu-m; (4) diameter of active area, 6 mm; (5) resistance, 600-OMEGA to 1 k-OMEGA.