Colloidal quantum dots, as well as similar crystalline quantum dots, have their functioning governed by quantum mechanics. Nanoparticles grouped in a nucleus surrounded by organic molecules, are semiconductors and, therefore, chosen by researchers at the University of California and the Los Alamos National Laboratory (LANL) to make their use in circuits an alternative to silicon-based microelectronics.
The two teams used quantum dot transistors to create circuits capable of performing logical operations, combining inorganic semiconductors with the chemical processability of molecular systems. The result was a functional CMOS circuit – a low-cost and ideal alternative for complicated electronic devices, but which can be manufactured using simple techniques based on alternative solutions.
A CMOS circuit (complementary metal-oxide-semiconductor, or complementary semiconductor of metal oxide) is composed of pairs of transistors of types p (positive) and n (negative), difficult to be produced. CMOS is the basic technology for integrated circuits of microprocessors, microcontrollers, RAM memories, memory chips, image sensors and other digital circuits.
However, making them depends on high-purity silicon, processed in aseptic environments, which raises its price. The search for circuits that can be manufactured at low cost using chemical processes has presented alternatives to the use of silicon in microelectronics, and colloidal quantum dots are one of them.