engineering

List of semiconductor materials

List of semiconductor materials is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand List of semiconductor materials rather than just read about it. In short: Semiconductor materials are nominally small band gap insulators. The defining property of a semiconductor material is that it can be compromised by doping it with impurities that alter its electronic properties in a controllable way.

Key takeaways

List of semiconductor materials belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect List of semiconductor materials to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of List of semiconductor materials from memory before moving on to harder problems.

Reference excerpt

Semiconductor materials are nominally small band gap insulators. The defining property of a semiconductor material is that it can be compromised by doping it with impurities that alter its electronic properties in a controllable way. Because of their application in the computer and photovoltaic industry—in devices such as transistors, lasers, and solar cells—the search for new semiconductor materials and the improvement of existing materials is an important field of study in materials science. Most commonly used semiconductor materials are crystalline inorganic solids. These materials are classified according to the periodic table groups of their constituent atoms. Different semiconductor materials differ in their properties. Thus, in comparison with silicon, compound semiconductors have both advantages and disadvantages. For example, gallium arsenide (GaAs) has six times higher electron mobility than silicon, which allows faster operation; wider band gap, which allows operation of power devices at higher temperatures, and gives lower thermal noise to low power devices at room temperature; its direct band gap gives it more favorable optoelectronic properties than the indirect band gap of silicon; it can be alloyed to ternary and quaternary compositions, with adjustable band gap width, allowing light emission at chosen wavelengths, which makes possible matching to the wavelengths most efficiently transmitted through optical fibers. GaAs can be also grown in a semi-insulating form, which is suitable as a lattice-matching insulating substrate for GaAs devices. Conversely, silicon is robust, cheap, and easy to process, whereas GaAs is brittle and expensive, and insulation layers cannot be created by just growing an oxide layer; GaAs is therefore used only where silicon is not sufficient. By alloying multiple compounds, some semiconductor materials are tunable, e.g., in band gap or lattice constant. The result is ternary, quaternary, or even quinary compositions. Ternary compositions allow adjusting the band gap within the range of the involved binary compounds; however, in case of combination of direct and indirect band gap materials there is a ratio where indirect band gap prevails, limiting the range usable for optoelectronics; e.g. AlGaAs LEDs are limited to 660 nm by this. Lattice constants of the compounds also tend to be different, and the lattice mismatch against the substrate, dependent on the mixing ratio, causes defects in amounts dependent on the mismatch magnitude; this influences the ratio of achievable radiative/nonradiative recombinations and determines the luminous efficiency of the device. Quaternary and higher compositions allow adjusting simultaneously the band gap and the lattice constant, allowing increasing radiant efficiency at wider range of wavelengths; for example AlGaInP is used for LEDs. Materials transparent to the generated wavelength of light are advantageous, as this allows more efficient extraction of photons from the bulk of the material. That is, in such transparent materials, light production is not limited to just the surface. Index of refraction is also composition-dependent and influences the extraction efficiency of photons from the material.

Types of semiconductor materials Group III elemental semiconductors, (B) Group IV elemental semiconductors, (C, Si, and Ge) Group IV compound semiconductors Group VI elemental semiconductors, (Se and Te) III–V semiconductors: Crystallizing with high degree of stoichiometry, most can be obtained as both n-type and p-type. Many have high carrier mobilities and direct energy gaps, making them useful for optoelectronics. (See also: Template:III-V compounds.) II–VI semiconductors: usually p-type, except ZnTe and ZnO which are n-type I–VII semiconductors IV–VI semiconductors V–VI semiconductors II–V semiconductors I–III–VI2 semiconductors Oxides Layered semiconductors Magnetic semiconductors Organic semiconductors Charge-transfer complexes Some of MOFs. Others

Compound semiconductors

A compound semiconductor is a semiconductor compound composed of chemical elements of at least two different species. These semiconductors form in periodic table groups 13–15 (old names IIIA-VA). The range of possible formulae is quite broad because these elements can form binary (two elements, e.g. gallium(III) arsenide (GaAs)), ternary (three elements, e.g. indium gallium arsenide (InGaAs)) and quaternary alloys (four elements) such as aluminium gallium indium phosphide (AlInGaP)) alloy and indium arsenide antimonide phosphide (InAsSbP). The properties of III-V compound semiconductors are similar to their group IV counterparts. The higher ionicity in these compounds, and especially in the II-VI compound, tends to increase the fundamental bandgap with respect to the less ionic compounds.

Fabrication Metalorganic vapor-phase epitaxy (MOVPE) is the most popular deposition technology for the formation of compound semiconducting thin films for devices. It uses ultrapure metalorganics and/or hydrides as precursor source materials in an ambient gas such as hydrogen. Other techniques of choice include:

Molecular-beam epitaxy (MBE) Hydride vapor-phase epitaxy (HVPE) Liquid phase epitaxy (LPE) Metal-organic molecular-beam epitaxy (MOMBE) Atomic layer deposition (ALD)

Table of semiconductor materials

Table of semiconductor alloy systems The following semiconducting systems can be tuned to some extent, and represent not a single material but a class of materials.

See also Heterojunction Organic semiconductors Semiconductor characterization techniques

References

Worked examples

Example 1 — a first encounter with List of semiconductor materials

Start with the simplest possible case. Write down what List of semiconductor materials claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to List of semiconductor materials before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about List of semiconductor materials ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of List of semiconductor materials

In research: List of semiconductor materials appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses List of semiconductor materials in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: List of semiconductor materials is common in secondary-school and first-year university syllabi. It links to neighbouring topics Semiconductor materials, so understanding it makes those chapters shorter.
In everyday life: Look for List of semiconductor materials outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study List of semiconductor materials in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what List of semiconductor materials means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain List of semiconductor materials out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is List of semiconductor materials in simple terms?

Why does List of semiconductor materials matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study List of semiconductor materials?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on List of semiconductor materials.