Molecular Ruler for Quantifying Steady-State and Population Distribution of Photo-Generated Charge Carriers

Provides Quantitative Information on the Steady-State Hot Carriers in Semiconductor and Metal Nanocrystals

This DNA-based molecular ruler quantitatively measures the steady-state energy and population distribution of plasmon-generated hot carriers in metal nanocrystals. Photo-generated charge carriers, such as plasmon-generated hot electrons and holes, are promising for solar-to-chemical energy conversion. The plasmonic materials market was valued at $12.36 billion in 2023 and is expected to grow to $51.75 billion by 20331. However, there is a significant lack of information on plasmon-generated hot carriers, including their steady-state energy and population distributions.

 

The steady-state energy and population distribution of photogenerated electrons and holes defines the energy-resolved probability distribution of charge carriers under continuous optical excitation, when photocarrier generation and relaxation exist in a dynamic equilibrium. SSEPD is a key parameter for assessing photon-to-electron conversion under practical operating conditions, as the performance of light-driven systems is not determined by the total number of generated carriers but by the population of carriers available at specific energy levels. This information is critical for real-life applications, including photocatalysis, photovoltaics, photosensors, photodetectors, and photoelectrochemical devices. However, no direct experimental technique currently exists for measuring steady-state energy and population distribution.

 

 

Researchers at the University of Florida have developed a DNA-based molecular ruler and established the first benchmark reference for the steady-state energy and population distributions of hot carriers. The ruler reveals that photocatalytic activity is directly correlated with the steady-state energy and population distribution of photogenerated electrons and holes, establishing steady-state energy and population distribution as a critical parameter for evaluating, predicting, and optimizing the performance of photocatalytic systems under practical operating conditions. Therefore, this ruler has the potential to significantly improve the practical application of photo-generated charge carriers and effectively reach the market. It is noted that, because the technology is not limited to a specific material class, it can be broadly applied to metallic, semiconductor, and hybrid materials to provide steady-state energy and population distribution information directly relevant to industrial applications, including photosensors, solar cells, photodetectors, photocatalysts, and photoelectrochemical energy-conversion devices.

 

 

Application

 

A molecular ruler that quantitatively measures the steady-state energy and population distribution of photo-generated charge carriers

 

Advantages

 

  • Provides direct access to steady-state energy and population distribution, revealing a critical but previously unmeasured parameter governing photon-to-electron conversion and carrier utilization in light-driven systems
  • Resolves both carrier energy and carrier population, enabling more accurate evaluation of photogenerated charge carriers than methods based only on absorption, photocurrent, or final device output
  • Broadly applicable to metals, semiconductors, and hybrid systems, supporting the design, screening, and optimization of materials and devices for photocatalysis, photovoltaics, sensing, and other optoelectronic applications

Technology

Photo-generated charge carriers are fundamental to light-driven energy conversion and optoelectronic technologies. However, practical application and performance optimization of these systems are limited by the lack of direct methods to determine the steady-state energy and population distribution of photogenerated electrons and holes under continuous operating conditions. Researchers at the University of Florida have developed a molecular ruler that directly quantifies the steady-state energy and population distribution of photogenerated charge carriers. This breakthrough enables more precise characterization, screening, and optimization of light-driven materials and devices, with potential impact in photocatalysis, photovoltaics, sensing, semiconductor technologies, and other optoelectronic applications.

Patent Information: