Ultrafast differential transmission spectroscopy is used to explore temperature-dependent carrier dynamics in an InAs/InGaAs quantum dots-in-a-well heterostructure. Electron-hole pairs are optically injected into the three dimensional GaAs barriers, after which we monitor carrier relaxation into the two dimensional InGaAs quantum wells and the zero dimensional InAs quantum dots by tuning the probe photon energy. We find that carrier capture and relaxation are dominated by Auger carrier-carrier scattering at low temperatures, with thermal emission playing an increasing role with temperature. Our experiments provide essential insight into carrier relaxation across multiple spatial dimensions.
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http://dx.doi.org/10.1364/oe.16.001165 | DOI Listing |
Environ Monit Assess
January 2025
Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh, India.
In recent years, heightened concern has emerged regarding the pervasive presence of microplastics in the environment, particularly in aquatic ecosystems. This concern has prompted extensive scientific inquiry into microplastics' ecological and physiological implications, including threats to biodiversity. The robust adsorption capacity of microplastic surfaces facilitates their widespread distribution throughout aquatic ecosystems, acting also as carriers of organic pollutants.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
College of Physics Science and Technology, Yangzhou University, Yangzhou 225009, China.
Developing high-performance solar cells is a practical way to improve clean energy conversion efficiency. However, the performance of solar cells faces challenges such as fast carrier combination, poor stability, and limited solar light harvesting. Herein, we propose a strategy by decorating periodic holes in two-dimensional (2D) porous carbon-nitrogen (CN) materials with a zero-dimensional (0D) semiconducting (ZnO) cluster.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China.
Materials with full and fractional skyrmions are important for fundamental studies and can be applied as information carriers for applications in spintronics or skyrmionics. However, creation, direct optical observation and manipulation of different skyrmion textures remain challenging. Besides, how the transformation of skyrmion textures directs the dynamics of colloids is not well understood.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Center for Physical Sciences and Technology, Saulėtekio av.3, 10257 Vilnius, Lithuania.
Understanding the dynamics of injected charge carriers is crucial for the analysis of the perovskite light-emitting diode (PeLED) operation. The behavior of the injected carriers largely dictates the external quantum efficiency (EQE) roll-off at high current densities and the temperature dependence of the EQE in PeLEDs. However, limitations such as sample capacitance and external circuitry hinder precise control of carrier injection rates, making it challenging to directly track the dynamics of individual carriers.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States.
The polycrystalline nature of perovskites, stemming from their facile solution-based fabrication, leads to a high density of grain boundaries (GBs) and point defects. However, the impact of GBs on perovskite performance remains uncertain, with contradictory statements found in the literature. We developed a machine learning force field, sampled GB structures on a nanosecond time scale, and performed nonadiabatic (NA) molecular dynamics simulations of charge carrier trapping and recombination in stoichiometric and doped GBs.
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