Perhaps this link may help..
**broken link removed**
Mr Friedrichs puts theory into practice and makes his own thermionic devices ( vacuum tubes ) but has on occasion made his own transistors all wonderfully documented in his books, he also describes a posibble method for home contruction of FET's and more interestingly a brief reference to the work of Robert Pohl and Rudolph Hilsch and the experiments using whole crystals as a semicondutor without the need for complex doping or contruction methods.