Researchers from the Skolkovo Institute of Science and Technology (Skoltech) have discovered why, after being chemically cleaned and dried, quantum dots and nanorods become brighter. It turns out that the chemical composition and internal structure of these semiconductor nanostructures change; some defects causing the luminescence to decay are eliminated, while the number of radiative recombination centers increasing significantly as a result.

Quantum dots and nanorods are semiconductor nanocrystals with unique optical properties that make them promising materials for use in various optoelectronic devices, including lasers, LEDs, solar cells, and photodetectors. However, the efficiency of such devices is often limited by the low quantum yield of quantum dots and nanorods, which is due to the presence of various defects and impurities in their structure.

In order to improve the performance of optoelectronic devices, it is necessary to increase the quantum yield of quantum dots and nanorods. This can be achieved by either eliminating the defects and impurities, or by increasing the number of radiative recombination centers.

In their work, Skoltech researchers discovered that chemical cleaning and drying of quantum dots and nanorods can significantly increase their quantum yield. They found that the chemical composition of the nanostructures changes after cleaning, with some defects being eliminated. In addition, the number of radiative recombination centers increases dramatically, which leads to an increase in the luminescence intensity.

Thus, it has been shown that chemical cleaning and drying can be used as an effective method to improve the quantum yield of quantum dots and nanorods, and thereby increase the efficiency of optoelectronic devices based on these materials.

The results of the study were published in the journal Nanoscale.