Quantum dot research: Current state and future prospects

This article reviews the current state of research involving semiconductor quantum dots, provides a brief review of the theory behind their unique properties, and an introduction explaining the importance of quantum dot research. The characteristic shifting of the band gap energy with quantum dot size, as predicted from the density of states for low-dimensional structures, allows experimental measurements to determine the extent to which quantum confinement effects play a role in the resulting properties. A few of the current techniques used to measure the presence and physical characteristics of quantum dots and their energy levels is reviewed, including transmission electron microscopy, optical transmission, and Raman and photoluminescence spectroscopy. Finally, some of the more exciting applications for quantum dots currently being researched for use in the field of optoelectronics are reviewed, including quantum dot infrared photodetectors, quantum dot lasers, and quantum dot solar cells. Comments are made on the current progress and the future prospects of quantum dot research and device applications.