The diode is one of the most commonly adopted and simply made elementary component in semiconductor technology. It’s been the basic starting brick for the construction of all electronic technology, discrete at the beginning and later integrated.
How does a diode work?
It simply allows the flow of the current in one direction and not in the opposite. The flow of current is inducted by an electrical field that creates a difference of electric potential between two different points of an electronics circuit … till now.
Nowadays a new solution has been introduced: the thermic diode (see Figure 1)
The basic principle of the working of the thermic diode is to use the difference in heat between two electrodes to move the electrons in a preferred direction: the heat is transferred from a terminal, a superconductor, to another terminal, which is constituted by a metallic material, and the opposite transfer is instead inhibited, this is done on purpose, by designing specific paths to dissipate the heat in this case.
The thermic diode is thus basically constituted by a couple of terminals, a junction superconductor-metal as anode and cathode and the electron flow is utilized to transfer heat and not to dissipate it: this diode hence holds promises of exceptional thermal performances, in terms of totally unexpected high efficiencies in terms of power management.
The possible scenario of application is wide, ranging from supercomputers that can operate at very high frequencies, because of their stability in temperature, to more in general phononics and coherent caloritronics applications.
The thermal vibration inside a semiconductor crystal is utilized to carry information, by being a major carrier, this is the basic idea of phononics which is quite similar to the photonics approach (in this case the major carriers are photons that are composed of quantum of light). The thermic impulse may enable the channel of a MOS transistor in a mode similar to voltage enabled components, actually utilized in electronics technology, and it is possible to create circuits to perform all of the basic operations like logic circuits and memory storage.
It’s the technology whose goal is to control the heat transfer by means of an electron flux, the heat is exchanged between two coupled superconductors:
The drain temperature of a SQUID (superconducting quantum interference device) as its source terminal is heated. (Source CNRNANO)
In the second part of this blog series, The thermic diode, a new potentially revolutionary simple electronic element, Part 2 I will deal with the strengths and the potentialities of the “thermal electronics” that is a fast growing sector in the field of electronic technology.