http://ceit.aut.ac.ir/~shiry/lecture/Electronics/Diods.ppt

http://en.wikipedia.org/wiki/P%E2%80%93n_junction

http://hyperphysics.phy-astr.gsu.edu/hbase/solids/pnjun.html

http://www.acsu.buffalo.edu/~wie/applet/pnformation/pnformation.html

http://www.allaboutcircuits.com/vol_3/chpt_2/6.html

http://www.solar.udel.edu/ELEG620/04_pnjunction.pdf

http://www.cleanroom.byu.edu/pn_junction.phtml

http://www.google.com/#q=p-n+junction&hl=fa&prmd=imvnsb&ei=tVwvUKq6CfOB4ASM1IDYCw&start=10&sa=N&bav=on.2,or.r_gc.r_pw.&fp=d3958e1590017180&biw=1016&bih=466

http://www.ee.sc.edu/personal/faculty/simin/ELCT566/16%20P-n%20Junction%20depletion%20region.pdf

http://users.ece.gatech.edu/phasler/Courses/ECE4430/Unit1/LectureNotes/day01.pdf