title: Mutual passivation of electrically active and isovalent impurities.
abstract: The alloy GaN(x) As(1-x) (with x typically less than 0.05) is a novel semiconductor that has many interesting electronic properties because of the nitrogen-induced dramatic modifications of the conduction band structure of the host material (GaAs). Here we demonstrate the existence of an entirely new effect in the GaN(x) As(1-x) alloy system in which the Si donor in the substitututional Ga site (Si(Ga)) and the isovalent atom N in the As sublattice (N(As)) passivate each other's electronic activity. This mutual passivation occurs in Si-doped GaN(x) As(1-x) through the formation of nearest-neighbour Si(Ga) -N(As) pairs and is thermally stable up to 950 degrees C. Consequently, Si doping in GaN(x) As(1-x) under equilibrium conditions results in a highly resistive GaN(x) As(1-x) layer with the fundamental bandgap governed by a net 'active' N, roughly equal to the total N content minus the Si concentration. Such mutual passivation is expected to be a general phenomenon for electrically active dopants and localized state impurities that can form nearest-neighbour pairs.
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA. kmyu@lbl.gov
authors.forename: K M
authors.initials: KM
authors.lastname: Yu
authors.forename: W
authors.initials: W
authors.lastname: Walukiewicz
authors.forename: J
authors.initials: J
authors.lastname: Wu
authors.forename: D E
authors.initials: DE
authors.lastname: Mars
authors.forename: D R
authors.initials: DR
authors.lastname: Chamberlin
authors.forename: M A
authors.initials: MA
authors.lastname: Scarpulla
authors.forename: O D
authors.initials: OD
authors.lastname: Dubon
authors.forename: J F
authors.initials: JF
authors.lastname: Geisz
mesh_terms: D000497:Alloys / Q000737:chemistry*; D001151:Arsenic / Q000737:chemistry*; D001152:Arsenicals / Q000138:chemical synthesis*; D003460:Crystallization / Q000379:methods*; D003461:Crystallography / Q000379:methods; D017097:Electric Impedance; D005708:Gallium / Q000737:chemistry*; D008422:Materials Testing / Q000379:methods*; D009584:Nitrogen / Q000737:chemistry*; D012666:Semiconductors; D012680:Sensitivity and Specificity; D012825:Silicon / Q000737:chemistry*; D013696:Temperature
chemical_list: D000497:Alloys; D001152:Arsenicals; C473312:GaNAs alloy; C043055:gallium arsenide; D005708:Gallium; D001151:Arsenic; D009584:Nitrogen; D012825:Silicon