(a)
Interpretation:
What type of semiconductor that would be formed from the given combination of elements has to be explained.
Concept Introduction:
Semiconductors are substances that conduct electricity either by addition of an impurity or by the effects of temperature on it. Semiconductors electrically conductivity lie between conductor and insulator. Semiconductors have small energy gap between valence band and conduction band.
Addition of impurity to a semiconductor is termed as doping. Doping alters the conductivity of a semiconductor. The addition of an element having either more or less number of valence electrons than the natural semiconductor decides the combination as the following two types of semiconductor.
- n- type semiconductor: (conduction is due to movement of extra electrons)
The element added will have more valence electron than the natural semiconductor. Therefore, the extra electron from the added element resides in conduction band and increase the conductivity.
Example: Silicon (natural semiconductor) and Phosphorus
- p-type semiconductor: (conduction is due to movement of holes)
The element added will have less valence electron than the natural semiconductor. Here, instead of extra electron, there will be “holes” at the places, where a semiconductor is replaced by added element. A p-type semiconductor increases conductivity because the holes (effective positive charge; lies at valence band) move through the natural semiconductor rather than electrons.
Example: Silicon (natural semiconductor) and Gallium
(b)
Interpretation:
What type of semiconductor that would be formed from the given combination of elements has to be explained
Concept Introduction:
Semiconductors are substances that conduct electricity either by addition of an impurity or by the effects of temperature on it. Semiconductors electrically conductivity lie between conductor and insulator. Semiconductors have small energy gap between valence band and conduction band.
Addition of impurity to a semiconductor is termed as doping. Doping alters the conductivity of a semiconductor. The addition of an element having either more or less number of valence electrons than the natural semiconductor decides the combination as the following two types of semiconductor.
- n- type semiconductor: (conduction is due to movement of extra electrons)
The element added will have more valence electron than the natural semiconductor. Therefore, the extra electron from the added element resides in conduction band and increase the conductivity.
Example: Silicon (natural semiconductor) and Phosphorus
- p-type semiconductor: (conduction is due to movement of holes)
The element added will have less valence electron than the natural semiconductor. Here, instead of extra electron, there will be “holes” at the places, where a semiconductor is replaced by added element. A p-type semiconductor increases conductivity because the holes (effective positive charge; lies at valence band) move through the natural semiconductor rather than electrons.
Example: Silicon (natural semiconductor) and Gallium
Want to see the full answer?
Check out a sample textbook solutionChapter 24 Solutions
Chemistry: Atoms First
- 8.96 A business manager wants to provide a wider range of p- and n-type semiconductors as a strategy to enhance sales. You are the lead materials engineer assigned to communicate with this manager. How would you explain why there are more ways to build a p-type semiconductor from silicon than there are ways to build an n-type semiconductor from silicon?arrow_forwardDefine a semiconductor? Describe the two main types of semiconductorswhen it is doped with(a) group 13 element, (b) group 15 element.arrow_forwardClassify as n-type or p-type a semiconductor formed by doping (a) germanium with phosphorus, (b) germanium with indium.arrow_forward
- Which of these doped semiconductors would yield a p-type material? (a) Ge:P (b) Si:Ge (c) Si:Al (d) Ge:S (e) Si:N?arrow_forward(a) Why electrical conductivity of the semiconductor increases with increase in temperature? Illustrate and explain the above effect with hypothetical band energy diagrams, showing one at 25 °C and another at 50 °C? (b) The number average molecular weight of polyvinyl chloride (PVC) is 110000 g/mol and the Polydispersity index (PDI) is 1.3. What is the weight average molecular weight and degree of polymerization of PVC? Note: Molar mass of vinyl chloride is 62.498 g/molarrow_forwardExplain the terms : (a) Intrinsic semiconductor (b) Extrinsic semiconductor.arrow_forward
- Chemistry for Engineering StudentsChemistryISBN:9781337398909Author:Lawrence S. Brown, Tom HolmePublisher:Cengage LearningPrinciples of Modern ChemistryChemistryISBN:9781305079113Author:David W. Oxtoby, H. Pat Gillis, Laurie J. ButlerPublisher:Cengage Learning
- Chemistry: Principles and PracticeChemistryISBN:9780534420123Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward MercerPublisher:Cengage LearningPhysical ChemistryChemistryISBN:9781133958437Author:Ball, David W. (david Warren), BAER, TomasPublisher:Wadsworth Cengage Learning,Chemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning