Quantum dot solids hold the promise of replacing silicon wafers in a new generation of computer processors, some researchers theorize. Now, Cornell University investigators have reported a breakthrough in the creation of these potentially radical new electronic materials.
Single-crystal silicon wafers first made their appearance in the field of electronics in the 1950s. Now, researchers working with quantum dot solids — crystals made out of crystals — believe their preferred material could revolutionize the industry.
Quantum dot solids were created from nanocrystals of lead and selenium forged into larger crystals. These fragments were later merged into a two-dimensional superstructure of coherent square building blocks. Each crystal is directly attached to crystalline neighbors, without other atoms or molecules intervening. This property could make the superlattice an ideal ingredient for semiconductors of the future.
"As far as level of perfection, in terms of making the building blocks and connecting them into these superstructures, that is probably as far as you can push it," said Tobias Hanrath of the Robert Frederick Smith School of Chemical and Biomolecular Engineering at the university.
Earlier research, reported in 2013, involved the use of ligands, a type of connector molecule, to "tie together" the individual quantum dots. Electronic networking of the individual cells has been a primary challenge in the development of quantum dot solids. This new development may have finally cleared this significant technological hurdle.
Electron wave function in the new solid is hindered by the fact that crystals in the superlattice are inconsistent, reducing the efficiency of electronic transmission. Although the initial results of the study look promising, additional fine-tuning of the process could prove to be extraordinarily difficult.
Future research could examine of a similar technique could be applied to other artificial materials in the development of futuristic semiconductors.
If quantum dot solids are developed to their full potential, the material could have an impact on the world of electronics as great as that created by the silicon revolution six decades ago. Researchers who carried out this latest breakthrough believe the techniques they developed may provide a stepping stone for future discoveries.
Development of the new quantum dot solid was detailed in the journal Nature Materials.