Photoluminesence quantum yield (PLQY) Definition and applications

1. What is Photoluminesence quantum yield?

Photoluminescence quantum yield (PLQY) is a measure of the efficiency of photoluminescence. It is the ratio of the number of photons emitted by the material to the number of photons absorbed. This measurement is used to determine the effectiveness of the photoluminescent material in converting absorbed energy into emitted light.

By understanding the PLQY of a given substance, researchers can gain valuable insights into its properties and potential applications. For example, a high PLQY may indicate that a material is well-suited for use in optoelectronic devices such as solar cells, lasers, and light-emitting diodes (LEDs), while a low-PLQY may suggest that it is better suited for other applications.

In short, the photoluminescence quantum yield is a fundamental property that plays a crucial role in the study of various essential substances. 

2. Used for:

PLQY is a critical parameter in scientific research, especially in the field of chemistry. It provides information about the fundamental properties of photoluminescent materials, such as the nature of the excited state and the radiative and non-radiative rates of the material.

PLQY is also essential in material science, where it is used to assess the efficiency of photovoltaic (solar) cells, light-emitting diodes, and other optoelectronic devices. The measurement can help researchers optimize the performance of these devices and improve their energy efficiency by increasing PLQY

PLQY is highly valued in the industry as a quality control tool. It is used to ensure that the production of photoluminescent materials is consistent and high quality. The measurement is also used to compare the efficiency of competing materials and help companies choose the optimal material for their specific application.

3. Fundamentals of Measuring PLQY

Principles of PLQY Measurement

The measurement of PLQY involves exciting the material with a light source, usually a laser or an LED, and detecting the emitted light. The intensity of the emitted light is compared to the intensity of the absorbed light, which allows for the calculation of PLQY.

Techniques and Instruments

Several techniques and instruments are used to measure PLQY, including steady-state excitation, time-resolved emission, and absolute PLQY measurements. These techniques differ in their sensitivity, measurement time, and complexity.

Experimental Setup

The experimental setup for PLQY measurement usually involves a spectrometer, a light source, and a detector. The spectrometer is used to analyze the wavelengths of the emitted light, while the detector measures the intensity of the emitted light.

Figure 1. Measurement and calculation of Photoluminescence Quantum Yield (PLQY).

4. Applications:

There are many applications of PLQY in various industries:

PLQY in Solar Energy Industry

In the solar energy industry, PLQY measurements play a crucial role in the development of advanced solar cell materials. By measuring PLQY values, researchers can determine the efficiency of converting solar energy into electricity. This helps in identifying the best materials for manufacturing high-performance solar cells.

PLQY in the Field of Biology and Medicine

PLQY measurements are also used in biological and medical research. Researchers use PLQY values to evaluate the fluorescence of biological molecules such as proteins, enzymes, and DNA. This information helps in developing new diagnostic tools, fluorescent sensors, and imaging techniques for medical applications.

PLQY in Electronics and Telecommunications

PLQY measurements play a crucial role in the development of innovative technologies for electronics and telecommunications. By measuring PLQY values, researchers can identify the most efficient semiconductor materials for developing advanced electronic devices such as LEDs, solar cells, and photodetectors.