New Vitreous Semiconductors

Abstract

Coevaporation with vapor quenching has been used to combine metallic and nonmetallic elem.ents into new vitreous semiconductors. These binary glasses, formed with an excess of nonmetal over. a wide ran.ge of compositions exhibit semiconducting and optical properties differing from the correspondmg proper~Ies of either component alone or of any known crystalline compound formed between the comp.onents. Detal~e? investigation of the vitreous Bi-Se system indicates that an inten;ne?iate temperature :el?~n of the equilibrium phase diagram has been retained at room temperatU1:e. VanatIon of ban~¥aI?' resls~lv~ty, and phootosensitivity with composition are presented and interpreted m tenns of the eqUilibnum eXlstmg at ",620 C.

Improvement of reliability and speed of phase change memory devices with N7.9(Ge46.9Bi7.2Te45.9) films

“…It has been known that Bi can change the electronic configurations in chalcogenide types of glasses, which results in the changes in their electrical properties. 30,31 Bi enters the network in the form of a charged species and alters the ratio of Valence Alternation Pairs (VAPs) to such an extent that the Fermi level of the GeBiTe becomes unpinned. 32 It is also reported that Bi changes the coordination from threefold and fourfold showing a positive charge to twofold and sixfold showing a negative charge.…”

Optical band gap in relation to the average coordination number in Ge—S—Bi thin films

“…The goal was the preparation of new infrared photodetectors. At the same time, it was discovered that a small amount of Bi atoms incorporated in a selenium matrix changes the electrical conductivity from p to n type [3]. More recently, the possibility of making an all chalcogenide glass p-n junction based on the ability of Bi to change the conductivity type was demonstrated [4,5].…”