Effects of Pressure on the Zn Vacancy in ZnSe: Essential Role of Lattice Relaxation for a Basic C3y Defect
نویسندگان
چکیده
The photoluminescence (PL) and PL excitation (PLE) spectra of the isolated Zn vacancy sVZnd in ZnSe are measured under hydrostatic pressure to 50 kbar at 7 K. The PL band shifts with pressure, roughly 30% faster than the band gap. Compression decreases the Stokes shift, reflecting a reduction in the C3y lattice relaxation around the V 2 Zn site. Defect-molecule calculations show that this arises from the dominance of spring-constant stiffening over increased Jahn-Teller coupling. We determine the VZn configuration-coordinate diagram at high pressure. Compression deepens the energy of the V 2 Zn thermal level. [S0031-9007(98)07699-6]
منابع مشابه
Pitfalls of Using Pressure to Assign the Luminescence of Large-Lattice-Relaxation Defects
Deep defects are often assumed to be insensitive to applied pressure because of their localized character. However, in recent photoluminescence (PL) experiments, several deep acceptor bands in ZnSe were found to shift with pressure substantially faster than the ZnSe bandgap. This shows that the optical (viz., PL) levels of these acceptors become more shallow under compression, a result that, if...
متن کاملThe simultaneous effect of 3d impurities of transition metals and oxygen vacancy defect on TiO2 anatase and rutile
In this work, the formation of oxygen-vacancy defect in 3d metals-doped TiO2 anatase and rutile structures is first investigated. The systematic calculations of formation energy, crystalline stability, band structure and density of state (DOS) of TiO2 samples of anatase and rutile doped with 3d transition metals with and without oxygen defect is done using FHI-aims as a software package based o...
متن کاملVacancies, interstitials, and close Frenkel pairs on the zinc sublattice of ZnSe.
Zinc vacancies (VZn), zinc interstitials ~Zn i), and ;25 distinct VZn–Zn i Frenkel pairs of different lattice separations are observed in ZnSe by the optical detection of magnetic resonance in photoluminescence after 2.5 MeV electron irradiation in situ at 4.2 K. The stability, photoluminescence energy, anisotropy of production vs beam direction, plus exchange and dipole-dipole interactions in ...
متن کاملCOMPUTATIONAL ENUMERATION OF POINT DEFECT CLUSTERS IN DOUBLE- LATTICE CRYSTALS
The cluster representation matrices have already been successfully used to enumerate close-packed vacancy clusters in all single-lattice crystals [I, 2]. Point defect clusters in double-lattice crystals may have identical geometry but are distinct due to unique atomic postions enclosing them. The method of representation matrices is extended to make it applicable to represent and enumerate ...
متن کاملSimulating far infrared spectra of Zn1-xMnxSe/GaAs epifilms, MnSe/ZnSe superlattices and predicting impurity modes of N, P defects in Zn1-xMnxSe
A comprehensive lattice dynamical study is reported to emphasize the vibrational behavior of perfect/imperfect zinc-blende (zb) ZnSe, MnSe and Zn1-xMnxSe alloys. Low temperature far-infrared (FIR) reflectivity measurements performed on a series of molecular beam epitaxy grown Zn1-xMnxSe/GaAs (001) epilayers have a typical 'intermediate-phonon-mode' behavior. Besides perceiving ZnSe- and MnSe-li...
متن کامل