Doping semiconductors compounded from various element groups

[Matthew Strasiotto]

Hi all - This is pulled from a past paper -

Homework Statement

I'm only going to state the components that I find challenging of this problem - The rest will be attached in my solution set.

Essentially - given an intrinsic semiconductor comprised of group II-VI elements.
Upon doping with group V, what's the resultant type of doping achieved?
My assumption - As will be seen in my uploaded solutions - is that I can approximate an "average" semiconductor group of halfway between 2 and 6, and dope this with group 5.

Additionally - I'd like to clarify my answer for 7ciii vs 7a, as they ask similar questions, and receive very similar answers by very similar methods.
It feels deceptively trivial reaching the answer I did for 7ciii, given I'd just applied nearly identical methodology in 7a.

Homework Equations

Taken from my annotated formula sheet - sorry about the hideousness
(OneNote version may be accessed as follows) https://www.physicsforums.com/onenote:https://d.docs.live.net/c82407cf764b2842/Documents/PHYS2213/Formula%20Sheets.one#SSD%20V2&section-id={48CAF64B-A001-43B7-8221-48C2D0C1B5D7}&page-id={104A1659-065B-41FD-95B8-3984FF56372D}&end (Web view)

The Attempt at a Solution

OneNote version: https://www.physicsforums.com/onenote:https://d.docs.live.net/c82407cf764b2842/Documents/PHYS2213/2016%20Exam.one#7a&section-id={D5534116-5EA0-45C3-9F75-315FE37CE3C4}&page-id={5FEBB6D7-983C-4DD5-8868-ACB5948F4492}&end (Web view)
PDF attached.
If this is not compliant with the homework template in some way - Please let me know, and I can make relevant edits.

 

[Matthew Strasiotto]

To answer my own question (An email from my UoS lecturer):
"Your answers are all correct except 7.b, where P atoms replaces group VI atoms and semi2 will be p-type."

I guess this means that I should just take the higher numbered group type as my basis of comparison to the dopant's group, for determining the resultant doping type?