Artistic view of the quasi two dimensional nano platelets. Image credit: Lauren Aleza Kaye / ETH Zürich
Researchers in Zurich have unlocked the method mechanism of nanoplatelet formation. Understanding this mechanism could lead to development of nanoplatelets as alternatives to quantum dots.
Nanoplatelets are a type of nanocrystal. These thin, two-dimensional structures have a uniform flat shape. Their thinness — often the width of a few atomic layers — gives them extremely pure color.
Until now, scientists did not understand the mechanism behind platelet formation. Previous theories posited the existence of a template that guided their formation. The research team, led by David Norris of ETH Zürich, discovered that platelets form by melting cadmium carboxylate and selenium.
Using this knowledge, the team theorized that the crystal forms spontaneously with a few cadmium and selenium atoms. After cycles of melting and reforming, the crystal achieves a critical size and grows into a platelet.
To confirm this theory, the team used their model to grow pyrite (FeS2) crystals. “It’s very interesting that we were able to produce these crystals for the first time with pyrite,” said Norris
Nanoplatelets have advantages that could appeal to the display industry. They generate some colors, such as green, better and brighter, and they transfer energy more efficiently. This later characteristic could be useful in lasers or solar cells.
Compared to quantum dots, however, nanoplatelets do not allow continuously variable color. The researchers propose that manufacturing variations could overcome these limitations.
