Why do quantum dots have advantages over quantum wells?

Question

Presently, semiconductor devices with active regions consisting of quantum dots have been researched as a replacement for quantum well based active regions. Why?

Answer 1

Typically, an active region will grow to its maximum extent in about 10 days and may persist for several months, declining slowly as its underlying magnetic fields dissipate. The sunspots that form within an active region usually disappear within 2–4 weeks.

Answer 2

One advantage of quantum dots lies in the fact that carriers are confined in all directions while in a quantum well carriers are only confined in the z-direction. The confinement of carriers reduces the density of states(DOS)- the number of states per unit energy. Reducing the DOS makes the quantum dots a more effective laser. An important aspect of a laser is the fact that the laser only emits one color or wavelength of light. However, that is not necessarily true for all lasers such as quantum well diode lasers. Quantum dots can theoretically emit only one wavelength of light similar to many gas lasers. However gas lasers are typically large and require sophisticated high energy power supplies while quantum dots are extremely small on the order of nanometers and require very little power.

Answer 3

Advantage ? All relative to the viewer. The quantum dots have a diferent quantum structure its a 3D structure it was more modes with which to play,

Each dot can have information

Answer 4

quantum dots allow for the processing of larger amounts of energy.