Nanotechnology and Advanced Spectroscopy

This is a world-renowned program, which combines efforts in advanced chemical synthesis, the state-of-art optical spectroscopy, and nanoscale devices

Quantum dot research at LANL has a long, more than two-decade history. It started with a handful of colorful fragments of semiconductor-doped glasses, brought to Los Alamos in 1995 by team’s founder, Victor Klimov. Over time this research has evolved into a comprehensive program spanning virtually all areas of quantum dot science from synthesis and advanced optical spectroscopy to theory and devices.

Quantum dots are tiny specs of semiconductor matter that are just a few nanometers across. The focus of Nanotech team’s research is on particles fabricated via colloidal chemistry known as colloidal or nanocrystal quantum dots. Because of their size-controlled electronic properties quantum dots can be viewed as ‘artificial atoms’ that can be engineered on demand to address a specific physical problem or a need of a certain application.

The studies of the Nanotech team have revealed many unusual and useful properties of quantum dots of great practical utility in numerous technologies including solar energy conversion, LEDs and displays, optical amplifiers and lasers, and flexible electronics. In particular, this team is responsible for the discoveries of nanocrystal lasing (Science 290, 314, 2000) and carrier multiplication (Phys. Rev. Lett. 92, 186601), and more recently, for groundbreaking work on luminescent sunlight collectors (Nature Phot. 12, 105, 2018), nanoscale single-dot light sources (Nature Mater. 18, 249, 2019), advanced solar cells (Nature Energy 5, 409, 2020), and new lasing concepts (Science 365, 672, 2019).

Effective defects: Defects are normally detrimental to the power conversion efficiency of solar cells. Du et al. show that in quantum-dot-sensitized solar cells charge-trapping defects assist photoconversion and increase efficiency by supporting charge transfer to the electrodes.

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