Silicon and germanium are both semiconducting elements that are important in electronics. Silicon is the most widely used semiconductor material and is present in sand and glass. It is used to make silicone polymers, semiconductor chips, optical glass, and solar panels. Germanium was discovered later than silicon and is also a semiconductor. While germanium was once used to make transistors, other semiconductors have replaced it for that purpose. Today, germanium oxide is mainly used in camera lenses and microscope lenses due to its optical properties. The key differences between silicon and germanium are that germanium has more electrons and higher conductivity, but silicon can operate at higher temperatures than germanium for semiconductor applications.

1. Silicon And Germanium
Presented By:
Shahzaib (Allahyar)Shar
16CHQ26

2. What is silicon?
Silicon is a chemical element (its symbol in
chemical formula expressions is "Si") that is
present in sand and glass and which is the best
known semiconductor material in electronic
components. Its atomic number is 14. The most
common isotope has atomic weight 28. In its
pure state, silicon is a metal-like substance with
an appearance and heft somewhat resembling
aluminum. In its natural state, silicon appears
bound up with other elements in the form of
compounds. It is abundant in the crust of the
earth.

3. Uses:
1:Silicones:
Silicon based polymers, known as silicones, provide an
alternative to environmentally harmful hydrocarbon
based products. We unknowingly use these polymers in
everyday items from lubricants, greases & resins to skin
and hair care products, antiperspirants, polishes, anti
foam agents and fabric softeners.

4. Silicon chips:
 The electronic products that we rely on
everyday cannot operate without semi-
conductor chips made from silicon.

5. Optical glass:
 Today’s modern high-speed
communications are made possible by
silicon. Optical glass produced from
silicon is used to manufacture both
optical fibre and liquid crystal displays.

6. Solar Energy:
 Silicon plays an important role in the
photovoltaic industries where solar
panels, made from silicon, use the sun’s
rays to generate space and water heating,
produce domestic and industrial
electricity and power remote
telecommunications, weather and
irrigation facilities

7. Physical Properties:
 Silicon is a metalloid, an element with
properties of both metals and non-metals.
Silicon exists in two allotropic forms. Allotropes
are forms of an element with different physical
and chemical properties. One allotrope is in the
form of shiny, grayish-black, needle-like
crystals, or flat plates. The second allotrope has
no crystal structure and usually occurs as a
brown powder
 The melting point of silicon is 1,410°C.

8. Chemical Properties:
 Silicon is a relatively inactive
element at room temperature. It does
not combine with oxygen or most
other elements. Water, steam, and
most acids have very little affect on
the element.

9. Germanium:
 Germanium was found by Clemens
Winkler in 1886.Germanium is a
chemical element with symbol Ge and
atomic number 32. It is a lustrous, hard,
grayish-white metalloid in the carbon
group, chemically similar to its group
neighbors tin and silicon. Pure
germanium is a semiconductor with an
appearance similar to elemental silicon.

10. Uses:
 Germanium is a semiconductor. The pure element was commonly
doped with arsenic, gallium or other elements and used as a
transistor in thousands of electronic applications. Today, however,
other semiconductors have replaced it.
 Germanium oxide has a high index of refraction and dispersion.
This makes it suitable for use in wide-angle camera lenses and
objective lenses for microscopes. This is now the major use for this
element.
 Germanium is also used as an alloying agent (adding 1%
germanium to silver stops it from tarnishing), in fluorescent lamps
and as a catalyst.

11. What is the difference between
Silicon and Germanium?
 • Germanium has d electrons, but Si does not.
 • Germanium atom has a larger radius than
silicon.
 • In a certain temperature, germanium will have
more free electrons than silicon. Thus, the
conductivity of germanium is higher.
 • When considering semiconductors of two
elements, silicon conductors are widely used
because they can be used at higher
temperatures than Ge conductors.

12.  Quaid-E-Awam University Of
Engineering, Science & Technology
Nawabshah