Band Diagram of Multi-Quantum Well Laser Diode

[rshalloo]

Homework Statement

This isn't for a homework problem per say, though it is a coursework question. I'm writing a lab report on Multi-Quantum Well Laser Diodes and am trying to explain the basic semiconductor physics behind it. As such I need a diagram of the band structure.

Homework Equations

N/A

The Attempt at a Solution

PICTURE HERE
This is what I have drawn up, but I just want to check if its correct or if I even have the right Idea. My way of looking at it is:
Its a PIN junction, usually a hetrostructure so we have the sunk in region in the center and then the active region is the I region, so the quantum wells will be contained there. The radiative recombination then occurs between the wells.

Any advice or comments on this would be much appreciated. Thanks very much

 

[mark726]

!

Hello there, great question! Your diagram looks to be on the right track. As you mentioned, the Multi-Quantum Well Laser Diode (MQW-LD) is a PIN junction with a heterostructure design. This means that it utilizes different types of semiconductor materials to create a well-defined band structure.

In your diagram, the central region with the quantum wells is where the active region is located. This is where the electrons and holes are confined to a narrow region, resulting in a higher probability of radiative recombination. The band structure in this region is typically designed to have a lower bandgap compared to the surrounding layers, which allows for efficient light emission.

One additional aspect to consider is the doping levels in the different regions of the MQW-LD. The P-doped region on one side and the N-doped region on the other create a built-in electric field, which helps to confine the electrons and holes to the active region. This also plays a role in the band structure and overall operation of the device.

Overall, your diagram is a good start in explaining the basic semiconductor physics behind the MQW-LD. Just make sure to mention the role of doping and the built-in electric field in your explanation. Good luck with your lab report!