Depletion zone of a n-i junction

[IRobot]

Hi,
I am interested in a junction between n doped and intrinsic GaAs, specifically the localization and width of the depletion zone (where the built-in E field is). In a p-n junction the depletion zone is calculated under the condition of electro-neutrality, if I see i-GaAs as really really low doped p-GaAs, can I consider that the depletion zone will be mostly in the i-GaAs? (I have in mind a juxtaposition of one layer of n-GaAs with a layer of i-GaAs which has twice the width of the first one)

 

[marcusl]

In a p-i-n structure, the depletion zone looks similar to that of a p-n but with the additional i region in the center. In photodiodes and RF switch devices, the i region width d is (I think) much larger than the widths of the depletion zones in the p and n layers, so the total depletion width will be a little larger than d.

 

[IRobot]

Well, in my case there is no p-layer behind the i region, the piece is really engineered like that. Or at least it is presented like that in the article based on this device.
At the moment, I am really inclined to look at the i region as a p region feebly doped in comparison to the n one, and in this case I would have a depletion layer entering over the i-GaAs.