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A Modular Microfluidic Technology for Systematic Studies of Colloidal Semiconductor Nanocrystals
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Carrier Multiplication Mechanisms and Competing Processes in Colloidal Semiconductor Nanostructures
Stephen V Kershaw1, Andrey L Rogach2
1Department of Materials Science and Engineering and Centre for Functional Photonics (CFP), City University of Hong Kong, Hong Kong S.A.R., China. skershaw@cityu.edu.hk.
Materials (Basel, Switzerland)
|September 21, 2017
Summary
Semiconductor nanoparticles can generate multiple excitons from a single photon via carrier multiplication (CM). Engineering nanoparticle properties can enhance CM efficiency and multiexciton lifetimes for better performance.
Area of Science:
- Materials Science
- Nanotechnology
- Quantum Physics
Background:
- Semiconductor nanoparticles exhibit broad absorption spectra, enabling the formation of hot excitons.
- Hot excitons can undergo cooling processes or carrier multiplication (CM), generating multiple excitons.
Purpose of the Study:
- To review the understanding of carrier dynamics in semiconductor nanoparticles.
- To guide the development of nanostructures for efficient CM and sustained multiexciton lifetimes.
Main Methods:
- Analysis of carrier cooling mechanisms (phonon-mediated, Auger cooling).
- Investigation of carrier multiplication (CM) as a competing process.
- Exploration of strategies to suppress non-radiative Auger recombination.
Main Results:
- Carrier multiplication (CM) competes with exciton cooling processes.
- Non-radiative Auger recombination limits multiexciton lifetimes.
- Nanoparticle engineering (shape, size, composition, heterostructures, surface treatments) can manipulate cooling and recombination.
Conclusions:
- Understanding carrier dynamics is crucial for optimizing CM in semiconductor nanoparticles.
- Tailoring nanostructures can favor efficient CM and prolong multiexciton lifetimes.
- This knowledge guides the design of advanced nanomaterials for enhanced optoelectronic applications.
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