'Smart' silicon: Switching between p- and n-conduction under compression

摘要

We report results of thermoelectric power (Seebeck effect) and Raman spectroscopy studies on undoped and Ge-doped (1.4-2.6 at. %) Czochralski-grown silicon under high pressure to ～17 GPa. Lattice dynamics of Si:Ge under compression resembles that in Ge-free silicon. But in contrary to undoped silicon, the electrical conduction in Si_(1-x)Ge_x may be reversibly (irreversibly) "switched" from p- to n-type by application of pressure of ～0.6GPa (～0.8-1.5 GPa). Under pressures higher than ～2GPa the samples turn to a compensated state. Thus, Si:Ge being a "smart" material that opens emergent perspectives for silicon-based devices. It may be utilized, e.g., as a "smart" substrate for integrated circuits or a "smart" layer in heterostructures.