QUANTUM DOTS: A BRIDGE BETWEEN QUANTUM MECHANICS AND ADVANCED TECHNOLOGIES

Abstract

Since the 1980s, it has been observed that spatially confined structures on the order of nanometers exhibit fascinating phenomena, opening new possibilities for research and applications in various scientific fields. Such rigorous spatial confinement results in quantum phenomena like excitations and tunneling playing a dominant role in charge transport. This has opened new research directions in microelectronics that utilize quantum phenomena. These new directions include the ability to create, characterize, and manipulate artificial structures whose features are controlled at the atomic level. They span diverse research areas such as mechanics, engineering, physics, chemistry, materials science, molecular biology, and medicine.

The fundamental components of modern electronic devices utilizing quantum phenomena are structures spatially confined in all three dimensions. Such quasi-zero-dimensional objects are called quantum dots (QDs).

Quantum dots are applied in both fundamental research and practical uses. Spatial confinement allows QDs to be treated as artificial atoms with controllable energy levels. This has proven invaluable in studying many-body phenomena occurring in solid materials, including e.g. strong electronic correlations, interferences, quantum decoherence, and spin effects. In parallel with these studies, quantum dots have also been explored for practical purposes. Their ability to absorb radiation at precisely defined wavelengths has led to the construction of photodetectors combining features such as high sensitivity, fast response time, and tunability. The same properties have enabled quantum dot technologies to be applied even in domestic environments. Quantum dot-based light-emitting diodes with well-defined wavelengths have been used to create QLED displays with unprecedented resolutions. In medicine, quantum dots are employed as tumor markers that selectively bind to cancer cells. Quantum dots also serve as the basic units in single-electron transistors.

This paper provides a comprehensive overview of the basic physics governing quantum dots, their unique properties, and the diverse range of applications stemming from their quantum confinement effects.