Lancaster: American Physical Society, 1952. 1st Edition. FIRST EDITION IN ORIGINAL WRAPS OF THE FIRST MODEL OF ELECTRON-HOLE RECOMBINATION IN A HIGHLY PURE SEMICONDUCTOR. Cited over 2500 since publication, this model is now known as the Shockley-Read-Hall (SRH) recombination and is of import to solar and semiconductor technology.
“Any electron which exists in the conduction band is in a meta-stable state and will eventually stabilize to a lower energy position in the valence band. When this occurs, it must move into an empty valence band state. Therefore, when the electron stabilizes back down into the valence band, it also effectively removes a hole. This process is called recombination” (Honsberg & Bowden, Types of Recombination).
The model Shockley and Read put forth in this paper is essentially recombination through defects; in other words, recombination does not happen in a pure material. The steps involved in SRH are two-fold: (1) “An electron (or hole) is trapped by an energy state in the forbidden region which is introduced through defects in the crystal lattice. These defects can either be unintentionally introduced or deliberately added to the material, for example in doping the material; and (2) If a hole (or an electron) moves up to the same energy state before the electron is thermally re-emitted into the conduction band, then it recombines.
“The rate at which a carrier moves into the energy level in the forbidden gap depends on the distance of the introduced energy level from either of the band edges. Therefore, if an energy is introduced close to either band edge, recombination is less likely as the electron is likely to be re-emitted to the conduction band edge rather than recombine with a hole which moves into the same energy state from the valence band. For this reason, energy levels near mid-gap are very effective for recombination” (ibid).
ALSO INCLUDED IN THIS ISSUE: Papers of significance by Abraham Pais, Vera Kistiakowsky, Robert Karplus, and Abraham Klein. Item #552
CONDITION & DETAILS: Lancaster: American Physical Society. Original Wraps. Complete. Professionally rebacked at the spine, very light library stamp on front and rear wrap. 4to (10.5 x 8 inches; 263 x 200mm). Original paper wraps – tight and solid -- in very good condition in every way.