If electron and hole recombine through mechanism called 'direct recombination' then electron+hole pair gives off light (that is the materials with direct bandgap)
if electron and hole pair recombination occurs through indirect recombination then electron+hole pair gives off heat (that is the materials with indirect bandgap).
hai,
you know that only electrons exist and holes are totally imaginary .as an hole is cteated when an electron is removed from neutral atom.and after the creation of an hole which is atom with an less electron .this causes more weight than an electron as atom consists of other electrons and also protons and neutrons:roll: :roll:
hi,
depending on the band gap....the wavelength will vary when the electron/s (or hole's) position shifts. so, in some cases the wavelength falls within visible light range and thus you see light.
What you might find interesting is that recently teams at CERN and the underground Gran Sasso Laboratory of the Italian National Institute of Nuclear Physics have conducted research with results that repeatedly indicated that the neutrinos had travelled at a velocity 20 parts per million faster than the speed of light.
It is difficult to foresee a U turn. It is like Improvements on Newtonian theory make Einstein's theory. One works in macro world the other can work in both macro and micro world.