Development of thermoelectric detectors on the basis of higher manganese silicide (HMS) films

It is known that HMS - MnSi_1.71-1.75 is an anisotropy degenerative semiconductor and has figure-of-merit Z=0.7x10^-3 K^-1 in the range T=400-1000K. It is used in production of high effective thermoelectric converters. Besides, HMS has high chemical and radioactive resistance. At first in the world practice, we developed and created the technology of production of poly crystalline MnSi_1.71-1.75 thin films on the silicon substrates. These MnSi_1.71-1.75 films have better thermoelectric and photoelectric parameters than MnSi_1.71-1.75 bulk single crystals. We also created the thermoelectric converters and the detectors of infrared radiation on basic MnSi_1.71-1.75 films with thickness d=1-20 μm. The phase and structural analyses of MnSi_1.71-1.75 films were carried out by X-ray reflection, electron diffraction and transmission electron microscopy methods. The analyses demonstrated that the MnSi_1.71-1.75 films have a polycrystalline columnar structure of crystallites the grown crystallites had the normal orientation with respect to the Si-substrate. The main parameters of the HMS thermoelectric converters and HMS IR-detectors were studied at T=400-1000 K. These devices are stable and have the sensitivity S=500-1000 μV/W the thermoelectric power α=150-250 μV/K and the response time τ≤10^-6 s at T=223- 1000 K. It is notified that the technology of production of MnSi_1.71-1.75- films and MnSi_1.71-1,75device is cheap and ecologically clean. Moreover, the devices were processed by ultrasonic at frequency f=3.5 MHz with intensity 1 W/cm² for 45 minutes at T=300 K. As a result, the thermo electromotive force has been increased significantly from the above range to α=360 - 400 μV/K.