Title: extrinsic defect
Long Title: IUPAC Gold Book - extrinsic defect
DOI: 10.1351/goldbook.14011
Status: current

Definition
Imperfection in a solid semiconductor (or insulator) connected with surface defects of any sort involving extrinsic chemical units in relation to the chemical formula of the solid, particularly adsorbed species of any sort.

Notes
1) These extrinsic surface defects play an essential role in heterogeneous photocatalysis. For example, they can serve as photocatalytic centres (sites). Surface defects, as well as bulk defects located in the near-surface region, can serve as entities that absorb ultraviolet, visible, or infrared radiation and generate free charge carriers. Surface defects can trap charge carriers and serve as recombination centres, thereby influencing the concentration of photocarriers at the surface of photocatalyst particles.
2) Doping of a catalyst creates an extrinsic defect.

Related Terms
- heterogeneous photocatalysis: https://goldbook.iupac.org//terms/view/14018
- photocarriers: https://goldbook.iupac.org//terms/view/14040
- photocatalytic centres: https://goldbook.iupac.org//terms/view/14043
- recombination centres: https://goldbook.iupac.org//terms/view/14081

Source
- PAC, 2011, 83, 931. 'Glossary of terms used in photocatalysis and radiation catalysis (IUPAC Recommendations 2011)' on page 952 (https://doi.org/10.1351/PAC-REC-09-09-36)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/14011/html
- json: https://goldbook.iupac.org/terms/view/14011/json
- xml: https://goldbook.iupac.org/terms/view/14011/xml

Citation: Citation: 'extrinsic defect' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.14011
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Accessed: 2026-06-29T13:28:12+00:00