http://www.profesormolina.com.ar/tutoriales/mater_semic.htm
http://www.scribd.com/doc/8241531/Fisica-Semiconductores
http://www.electronica-basica.com/semiconductores.html
http://www.uned.es/ca-bergara/ppropias/Morillo/web_et_dig/02_semiconduc/transistores.pdf
http://www.unicrom.com/Tut_diodozener_.asp
