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Updated: Jun 13, 2026
14:20
Absolute Quantum Yield Measurement of Powder Samples
Published on: May 12, 2012
Quantum yield: the term and the symbol. A historical search
Mordecai B Rubin1, Silvia E Braslavsky
1Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel. chrubin@tx.technion.ac.il
Summary
Einstein's Photochemical Equivalence Law, stating one light quantum absorbed per molecule, was crucial for early 20th-century photochemistry. This paper details the haphazard acceptance of quantum yield (Phi) terminology.
Area of Science:
- Photochemistry
- Quantum Mechanics
- Chemical Physics
Background:
- The early 20th century saw significant advancements in understanding light-matter interactions.
- Einstein's Photochemical Equivalence Law provided a foundational principle for photochemistry.
- This law posits that one quantum of light is absorbed per molecule undergoing a photochemical process.
Observation:
- The development of photochemical theory was closely linked to quantum principles.
- The concept of "quantum yield" emerged to quantify photochemical reaction efficiency.
- The symbol "Phi" (Φ) was adopted to represent quantum yield.
Findings:
- The paper examines the historical trajectory of the term "quantum yield" and its symbol.
- It highlights that the adoption of this terminology was not a systematic or planned process.
- The acceptance of "quantum yield" and "Phi" occurred in a rather "haphazard manner".
Implications:
- Understanding the historical context of scientific terminology aids in clear communication.
- The paper provides insight into the evolution of standard scientific language in photochemistry.
- Clarifying the origins of "quantum yield" (Φ) can prevent confusion in scientific literature.
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