Eric-- I was taught many years ago that the energy bands are determined by quantum mechanics of the semiconductor, a coherent system of particles with electrons occupying discrete energy levels in that system. There is no electrical wave that spreads throughout the semiconductor. It happens instantaneously, if a new electron enters the system—no delay.
If someone has an experiment that can sheds lighti on this question, I would be interested, Bob From: Eric Walker Sent: Sunday, June 28, 2015 8:05 PM To: [email protected] Subject: Re: [Vo]:Re: Single-catalyst water splitter from Stanford produces clean-burning hydrogen 24/7 On Sat, Jun 27, 2015 at 2:35 PM, Bob Cook <[email protected]> wrote: In my concept elements of a system—a QM system—are entangled and act coherently and instantaneously. Any two systems whose elements couple in any way constitute a coherent, although weakly coupled system. For example, introduction of an electron into a semiconductor instantaneously changes the energy level of every other electron in that semiconductor no matter their distance from the new electron just introduced. This seems mistaken. I would have expected there to be a wavefront for the propagation of the new Fermi level along the semiconductor at some speed up to the speed of light in a vacuum following upon the stimulation of an electron. Also, I believe a typical semiconductor system has so many electrons at so many energy levels that it is no longer useful to think of it as a quantum mechanical system -- hence the treatment of the band structure as a set of continuous ranges. Is this understanding incorrect? Eric
