chemistry

Indium phosphide

Indium phosphide is a chemistry 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 Indium phosphide rather than just read about it. In short: Indium phosphide (InP) is a binary semiconductor composed of indium and phosphorus. It has a face-centered cubic ("zincblende") crystal structure, identical to that of GaAs and most of the III-V semiconductors.

Key takeaways

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

Reference excerpt

Indium phosphide (InP) is a binary semiconductor composed of indium and phosphorus. It has a face-centered cubic ("zincblende") crystal structure, identical to that of GaAs and most of the III-V semiconductors.

Manufacturing

Indium phosphide can be prepared from the reaction of white phosphorus and indium iodide at 400 °C., also by direct combination of the purified elements at high temperature and pressure, or by thermal decomposition of a mixture of a trialkyl indium compound and phosphine.

Applications The application fields of InP splits up into three main areas. It is used as the basis for optoelectronic components, high-speed electronics, and photovoltaics

High-speed optoelectronics InP is used as a substrate for epitaxial optoelectronic devices based other semiconductors, such as indium gallium arsenide. The devices include pseudomorphic heterojunction bipolar transistors that could operate at 604 GHz. InP itself has a direct bandgap, making it useful for optoelectronics devices like laser diodes and photonic integrated circuits for the optical telecommunications industry, to enable wavelength-division multiplexing applications. It is used in high-power and high-frequency electronics because of its superior electron velocity with respect to the more common semiconductors silicon and gallium arsenide.

Optical Communications InP is used in lasers, sensitive photodetectors and modulators in the wavelength window typically used for telecommunications, i.e., 1550 nm wavelengths, as it is a direct bandgap III-V compound semiconductor material. The wavelength between about 1510 nm and 1600 nm has the lowest attenuation available on optical fibre (about 0.2 dB/km). Further, O-band and C-band wavelengths supported by InP facilitate single-mode operation, reducing effects of intermodal dispersion.

Photovoltaics and optical sensing InP can be used in photonic integrated circuits that can generate, amplify, control and detect laser light. Optical sensing applications of InP include

Air pollution control by real-time detection of gases (CO, CO2, NOX [or NO + NO2], etc.). Quick verification of traces of toxic substances in gases and liquids, including tap water, or surface contaminations. Spectroscopy for non-destructive control of product, such as food. Researchers of Eindhoven University of Technology and MantiSpectra have already demonstrated the application of an integrated near-infrared spectral sensor for milk. In addition, it has been proven that this technology can also be applied to plastics and illicit drugs.

References

Cited sources Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. ISBN 9781498754293.

External links Extensive site on the physical properties of indium phosphide (Ioffe institute) Band structure and carrier concentration of InP. InP conference series at IEEE Indium Phosphide: Transcending frequency and integration limits. Semiconductor TODAY Compounds&AdvancedSilicon • Vol. 1 • Issue 3 • September 2006

Illustrations

Worked examples

Example 1 — a first encounter with Indium phosphide

Start with the simplest possible case. Write down what Indium phosphide claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, 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 Indium phosphide 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 Indium phosphide 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 Indium phosphide

In research: Indium phosphide appears in chemistry 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 Indium phosphide 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: Indium phosphide is common in secondary-school and first-year university syllabi. It links to neighbouring topics IARC Group 2A carcinogens, III-V compounds, III-V semiconductors, so understanding it makes those chapters shorter.
In everyday life: Look for Indium phosphide 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 Indium phosphide in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Indium phosphide 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 Indium phosphide out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Indium phosphide in simple terms?

Why does Indium phosphide matter?

Because it connects several chemistry 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 Indium phosphide?

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 Indium phosphide.