On a critical artifact in the quantum yield methodology

TL;DR

This paper identifies a previously unrecognized flaw in the standard measurement of photoluminescence quantum yield, which causes underestimation due to parasitic absorption, and proposes a correction method to improve accuracy.

Contribution

It reveals a critical artifact in quantum yield measurement methodology and introduces a correction procedure to address parasitic absorption effects.

Findings

The standard QY measurement underestimates emission efficiency due to parasitic absorption.

The identified flaw is present under common experimental conditions.

A correction procedure effectively mitigates the underestimation issue.

Abstract

For the development and optimization of novel light emitting materials, such as fluorescent proteins, dyes and semiconductor quantum dots (QDs), a reliable and robust analysis of the emission efficiency is crucial. The emission efficiency is typically quantified by the photoluminescence quantum yield (QY), defined by the ratio of emitted to absorbed photons. We show that this methodology suffers from a flaw that leads to underestimated QY values, presenting as a 'parasitic absorption'. This effect has not been described and/or corrected for in literature and is present already under common experimental conditions, therefore, it is highly relevant for a number of published studies. To correct for this effect, we propose a modification to the methodology and a correction procedure.