Leakage current is less in silicon made devices than germanium made since its energy bandgap is more than that of germanium .
What is silicon leakage current?
An important conduction limitation of PN junction diode is leakage current. When a diode is reverse biased, the width of the depletion region increases. ... It is seen that in a reverse-biased diode, some current flows through the depletion region. This current is called leakage current.
Why reverse saturation current of silicon is less than germanium?
The silicon diode is less sensitive than the germanium diode, hence the operation of silicon diodes is stable with changes in temperature. The Si diode has low reverse current compared to Ge.
Why is Ge preferred over Si?
Ge has higher electron and hole mobility and because of this Ge devices can function up to a higher frequency than Si devices. The germanium diode is also superior to silicon diode in terms of energy loss, current loss, etc. The Ge diode loses only 0.3-0.4 a volt while a silicon diode loses about 0.6-0.7 volts.
Why is silicon more used than germanium?
Silicon crystals have fewer free electrons than germanium crystals at room temperature, which is why silicon crystals are used for semiconductor devices. In general, the ICBO of germanium is 10-100 times greater than that of silicon, but the variation of ICBo at any temperature is lower for silicon than for germanium.
What is leakage current in reverse biased?
Reverse leakage current in a semiconductor device is the current from that semiconductor device when the device is reverse biased. ... Reverse leakage current is also known as “ zero gate voltage-drain current ” with MOSFETs. The leakage current increased with temperature.
How can leakage current be reduced?
A typical method for the decrease in parasitic capacitor impedance is to augment the impedance along the path of leakage current. The coupled transformer featured with a galvanic isolation is the most representative to be widely employed either in AC circuit or DC circuit for suppressing the leakage current.
Is zener a diode?
A Zener diode is a silicon semiconductor device that permits current to flow in either a forward or reverse direction. The diode consists of a special, heavily doped p-n junction, designed to conduct in the reverse direction when a certain specified voltage is reached.
What is the reverse saturation current in silicon?
The reverse saturation current of a silicon diode is of the order of nano amperes (nA) . ∴ The silicon diode is operated as a good switch. The reverse saturation current of a Germanium diode is of the orders of micro-amperes (μA).
Why is Germanium preferred over silicon in Zener diode?
At room temperature, Silicon crystal has fewer free electrons than Germanium crystal. This implies that silicon will have much smaller Collector cut off current than Germanium. ... Peak Inverse Voltage ratings of Silicon diodes are greater than Germanium diodes. Si is less expensive due to the greater abundance of element.
What is difference between silicon and germanium?
Silicon is a chemical element with atomic number 14 and chemical symbol Si while germanium is a chemical element with atomic number 32 and chemical symbol is Ge. The key difference between silicon and germanium is that Germanium has d electrons , but Silicon does not have any d electrons.
Which has more conductivity silicon or germanium?
Each has four valence electrons, but germanium will at a given temperature have more free electrons and a higher conductivity. Silicon is by far the more widely used semiconductor for electronics, partly because it can be used at much higher temperatures than germanium.
Why is the cut in voltage of silicon and germanium different?
A silicon diode has a voltage drop of approximately 0.7V , while a germanium diode has a voltage drop of approximately 0.3V. Though germanium diodes are better in the area of forward voltage drop, silicon diodes are cheaper to produce and have higher breakdown voltages and current capabilities.
Why silicon is used in semiconductor?
Silicon, a very common element, is used as the raw material of semiconductors because of its stable structure . Purification of Silicon consumes large amounts of power. In Japan, refined Silicon (ingot) with purity of at least 98% is imported from Australia, China and Brazil, where electricity is relatively inexpensive.
Why SI is a better insulator than GE?
First reason is that Si forms on its surface very easily a thin layer of SiO2 which is a very good insulator and which technologically can be very easily processed. Ge has higher electron and hole mobilities and because of this Ge devices can function up to a higher frequency than Si devices.
Why is germanium used in transistors?
The superior electron and hole mobility of germanium as well as its low melting point has spurred much research into replacing current silicon based devices with germanium. The electron and hole mobility of a material is the rate at which the electrons and holes can move through the material.
