Talk:Julius Edgar Lilienfeld

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I'm interested in the source of any evidence that Lilienfeld DIDN'T build his devices. If we speculate that pure materials were needed and therefore his devices could not have worked, well, that's SPECULATION. (I vaguely remember a SciAm AMATEUR SCIENTIST project where thin-film transistors were made using fairly impure materials!) It was my impression that nobody knows whether Lilienfeld's devices worked or not. --Wjbeaty 19:55, Mar 20, 2005 (UTC)

Well, usually the chain of evidence is unraveled the other way around. There is no evidence that his devices worked, and the common consensus it that they probably did not.

Lack of proof does not constitute disproof; "absence of evidence is not evidence of absence." As applied to Lilienfeld, if there is no proof that his transistors displayed gain, then we can only conclude that nobody knows whether they worked. But if someone KNOWS that they didn't work, I want to hear their evidence. For example, did someone try replicating the devices from his patents... and fail? Or is there some theoretical reason why they should fail? As I understand it, ultra-pure materials are only required in grown-crystal devices. Crappy materials work fine for copper-oxide or selenium rectifiers, and possibly for the baked-chemicals semiconductors in that old SciAm article. Bell Labs was never able to make copper-oxide FETs because surface states act as a conductor and screen out the e-fields within the bulk material. I wonder, maybe the negative concensus about Lilienfeld is the "Emperor's Nose" phenomenon described by R. Feynman. Or maybe it's based on an assumption that Lilienfeld would have first had to conquer the "surface states problem." There was an old article in Analog SF magazine, "The 20 lost years of semiconductor physics" which speculated that his broken-glass-gold-foil transistor was actually NPN, not an FET (assumed that metal ions from the foil actually diffused into the thinfilm conductor, forming a narrow "base region" having reversed doping.) What if Lilienfeld's technique eliminates the Surface States Problem right off the bat? His transistors sound like an excellent physics-student project, but I wouldn't be suprised if lots of repeated attempts are needed to get the variables set right. --Wjbeaty 04:43, Mar 22, 2005 (UTC)

That said, I find these patents really fascinating. I am fairly sure that Lilienfeld knew what he did. I found several letters in old journals by him showing that he had a really good grasp of space charge limited currents - a theory that can be used to explain the operation of various types of transistors (although not commonly done so). It is also well established that he knew how to manufacture high quality thin film isolators, as evidenced by his groundbreaking work in electrolytic capacitors.

The description of his devices is very detailed down to the materials chosen. In theory his devices should work. --Qdr 23:17, 20 Mar 2005 (UTC)

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It is unclear why Lilienfeld did not receive a Nobel Prize for his pioneering work. Nobel Prizes are not awarded posthumously, but Lilienfeld was still alive when Shockley, Bardeen, and Brattain : each received 1/3 of the physics prize in 1956. The Nobel Committee, however, does not publish the reasons leading to its decisions.

The nobel price was obviously given for the first experimental and theoretical demonstration of the transistor. There are numerous other people who contributed and demonstrated related work, not limited to Lilienfeld. (O. Heil, H. Matare and H. Welker come to mind.) --Qdr 22:48, 27 August 2006 (UTC)

[edit] Interesting! Evidence of a Bell Labs' coverup

The semiconductor physicist H. E. Stockman says "Lilienfeld demonstrated his remarkable tubeless radio receiver on many occasions, but God help a fellow who at that time threatened the reign of the tube." See Bell Labs Memorial: Who really invented the transistor?, starting at "Oscillating Crystals".

Here's a paper which details some history of the laboratory testing of Lilienfeld's patent claims by others: The Other Transistor: early history of the MOSFET See pp235-236

Briefly: In 1964 a physicist V. Bottom asked in Physics Today magazine whether these transistors worked, and J. B. Johnson of Bell Labs responded saying that he'd tested them and they didn't work. This probably is the origin of the story that Lilienfeld never had any working hardware. Then in 1995 R. G. Arns found a 1948 legal deposition by Johnson which said the opposite: that Bell Labs back then had a project to test Lilienfeld's transistors, and before Johnson took over the project, Shockely and Pearson had built Lilienfeld's aluminum oxide MOSFET from his patent and found only an 11% modulation index, but that "useful power output is substantial"! To me this sounds like Johnson, being with Bell Labs, perhaps had an agenda to promote his own company's discovery while misleading the physics community about Lilienfeld's. After Shockley/Pearson's success, Johnson had tested the other two Lilienfeld patents and was unable to replicate them ...so Johnson was only dishonest in his covering up the fact that Bell Labs well knew that Lilienfeld had something real. Between these times B. Crawford in 1991 built successful but unstable Lilienfeld MOSFETs and saw evidence that Lilienfeld had done the same. In 1995 J. Ross built stable Lilienfeld MOSFETs. The author makes a very telling statement about the honesty of these scientists: "Published scientific, technical, and hstorical papers by these Bell scientists never mention either Lilienfeld’s or Heil’s prior work." --Wjbeaty 03:13, 1 November 2006 (UTC)

[edit] Transistors with 1920 technology

Just in case somebody is interested in how Julius Lilienfelds results can be replicated using 1920ies technologies. I found a paperJVST A Volume 20, Issue 4, pp. 1365-1368 describing transistors made with anodized aluminum gate insulator and a chemical bath deposited semiconductor (CdS/CdSe). Both are techniques that do not require complicated equipment (beaker, current source, heater) and should have been accessible in the 1920ies.

Bizarrely enough the same authors managed to file patent on their technique (US6225149), despite of all the prior art. (Using chemical bath deposition for transistors is not exactly a novel idea..) --Qdr 20:36, 2 January 2007 (UTC)