Thermoelectric cooling device

Thermoelectric cooling devices, treated in Chapter 46 Arsenic, Antimony and Bismuth, with bismuth telluride as semiconductor material, are utilized for cooHng purposes. 

On the high-pressure device, the infrared measurements are performed using a Bruker Tensor 37 FTIR spectrometer. The IR configuration includes a NIR source, the Tensor 37 interferometer with a CaF2 beam splitter and a thermoelectrically-cooled InAs detector. The UV Visible measurements are made using a Varian Cary 300 spectrometer equipped with 600 pm core diameter optical fibres. 

Because the dark current properties of SPD and MCP-SPD arrays are low and much of the dark current has thermal origins, the dark current can be substantially reduced by detector cooling. Most devices are equipped with Peltier-effect thermoelectric cooling systems coupled to cold liquid coolant systems to achieve temperatures as low as -40 to -80°C in some designs. 

The EMF measured by a readout device reflects the difference between the temperatures of the measuring junction and the reference junction thus, the temperature at the reference junction must be properly controlled. It is usually maintained at the freezing point of water (0°C) by using an ice bath (Fig. 16.23). The ice bath should be a mixture of crushed ice and pure water in a Dewar flask with considerably more ice than liquid. It can be very accurate but not too convenient in some applications, since frequent replacement of melted ice is required. With a thermoelectric refrigeration system [36], ice can be maintained by cooling the bath of water with thermoelectric cooling elements. 

This enhanced efficiency would result from a higher change-carrier mobility due to a greater density of states and more limited phonon transport. In fact, thermoelectric nanobased devices open a more diverse avenue of applications for increased spot cooling or for use as sensors, such as infrared or micro- and nanocalorimeter sensors [156]. 

Peltier effect A thermoelectric cooling effect used in small-scale refrigeration units. It involves a solid-state heat pump that transfers heat from one side of the device to the other through the consumption of electticity. The thermoelectric cooling effect is created between the junction of two different types of conducting materials. The device can also be used for heating. It is named after French physicist lean Charles Athanase Peltier (1785-1845) who discovered the effect in 1834. 

When incorporated into a thermoelectric device, this ZT value determines the maximum energy conversion efliciency for thermoelectric power generation ((Jmax) [10] and thermoelectric cooling ( /max) [11]. as shown in following Eqs. 1.2 and 1.3 ... 

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