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Questions tagged [semiconductors]

Semiconductors are materials with electrical conduction between that of conductors and insulators.

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What is the definition of a bipolaron and a dipolaron?

I wondered about the exact definition of a bipolaron? In particular, if I have an oxygen vacancy in a metal oxide and the 2 excess electrons (when forming a neutral oxygen vacancy) localise on the 2 ...
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What are the oxidation states of galium and arsenic in GaAs semiconductor?

According to the book I'm referring to ("S.M. Sze Semiconductor Devices"), gallium has an oxidation state of +1 and arsenic has that of -1. This should not be possible as each of these elements forms ...
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Why are silicon and germanium used as semiconductors but not other metalloids?

The semiconductor materials are either elementary such as silicon and germanium or compound such as gallium arsenide. Silicon is the most used semiconductor for discrete devices and integrated ...
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How to find out which organic molecules would be good electron acceptors/donors on a GaAs semiconductor surface [closed]

I'm a physicist in way over my head. I have a list of organic molecules to investigate, all common aldehydes and amines. My supervisor wishes to know which of these molecules would be good electron ...
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NiO and ZnO electrical conductivity with oxygen pressure

NiO is a Mott-Hubbard insulator and increasing oxygen concentration leads to anion excess and oxidation of Nickel so electron hopping is more favourable so electron repulsion is reduced and it becomes ...
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How to tell the needed doping element for semiconductors?

I was reading about a crystal that is a semiconductor, galena. I am confused on how to tell what elements are needed to dope it to make a p or n type semiconductor, as well as how to know which ...
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1answer
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Conductivity of a semiconductor at high temperatures

I understand that increasing the temperature of a semiconductor excites electrons in the valence band into the conduction band. Hence, the resistivity of a semiconductor decreases with temperature. ...
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1answer
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How to determine mobility when two mechanisms exist simultaneously

Two scattering mechanisms exist in a semiconductor. If only the first mechanism is present, the mobility will be $\pu{250 cm2/V s}$. If only the second mechanism is present, the mobility will be $\...
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1answer
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Conductivity of Wüstite

"Wüstite is often represented as $\ce{Fe_{1-x}O}$, where $x$ is some small fraction less than unity. In this nonstoichiometric $\ce{Fe_{1-x}O}$ material conduction is electronic and the material ...
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Band alignment of heterojunctions

I have seen several band bending diagrams in journals and the web. However, I am not sure as to how they align them. Some diagram appear to align the vacuum level and some align them by Fermi Level. I ...
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Why is it important to minimize impurities when doping a semiconductor?

I was reading "Electronic Devices and Circuits" by Boylestad, and in there the author talks about how the semiconductor industry seeks to add as little impurities as possible when manufacturing ...
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1answer
841 views

Why does Ga improve conductivity of Ge? [closed]

This is for my AP Chemistry course and the question is: Which of the following elements is important in the semiconductor industry to improve the conductivity of Ge? K Ga Al Mg ...
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What is the limiting value of band gap that makes a material semiconductor?

What is the limiting value of band gap (in eV) that makes a material semiconductor? Or what is the value of band gap that separates insulator and semiconductor?
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Why does phosphorus give a free electron in silicon doping?

Extrinsic semiconductors are created by doping an intrinsic semiconductor; typically silicon is doped with phosphorus to create free electrons or boron to create "holes". In the case of phosphorus ...
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What is a covalent semiconductor?

Aren't all semiconductors' atoms bond in a covalent bond? How is a "covalent semiconductor" different from other semiconductors?
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1answer
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Is the photoelectric effect possible for semiconductors?

Is the photoelectric effect possible for semiconductors? I imagine that this might be, if possible, a two-photon process: excitation of an electron from a filled to conductance band, and then on to ...
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Why is silicon used in computer chips?

Most computer chips contain or are made of silicon. Why silicon? Why not copper or tellurium or some such?
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What sort of molecules or polymers are used in OLED displays?

OLED displays have been emerging as competitors for LCD displays for some time and are now common in mobile phones (see comparison of a Google Nexus 1 and an iPhone here) The displays use small ...
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Choice of doping elements in semiconductors

In a typical semiconducting material, we start with silicon (group IV) and introduce atoms of group V or group III depending on whether we are constructing an n- or p-type semiconductor respectively. ...