The structure of radiative and non-radiative recombination centres in activated CdS phosphors

Abstract

The intensity of photoluminescence (PL) emission bands in quenched CdS: Cu: C1 powder samples is measured and i t turns out to be a power function of the concentrations of CI, Nci, and Cu, Ncur in the material. The simplifications in which case the quasichemical theory of defect formation in solids gives such a simple dependence are clarified. The method t o determine the structure of recombination centres in AIIBVI compounds, based on the comparison of experimental and theoretical graphs, is proposed. The method is used for clarifying the nature of rand k-PL centres (A, , , = 1030 n m and Amax = 780 nm, respectively) and s-centres of non-radiative recombination, and also predominant defects C1 and Cu in CdS:Cu: CI. The r-, k-and s-centres may be identified with the following defects of crystal lattice of CdS: r-centre -(CucdCls), k-centre -(Cued),;s-centre -(CUcdCUi)2 a t Ncu > Ncl and C1, a t Ncu < N a . The latter two turned out to be predominant defects of Cu and C1 a t corresponding relations of Ncu and Ncl. M3MepeHa KHTeHCIIBHOCTb aKTHBaTOPHbIX IIOJIOC @OTOJIlOMHHeCUeHUllll (@a) ,,MrHOBeH-HO" OXJIaXneHHblX~ 0 6 p a 3~0~ CdS: CU: C1, KOTOpaR OKa3aJIaCb CTeIleHHOfi @yHHUHeii OT CoDepwaWaxcR B MaTepMane HOHUeHTpaqIIfi C1, Ncl II CU, Ncu. BbIRCHeHbI YnpOUeHHR, IIpH H CTOJIL IIpOCTOB 3aBHCPlMOCTH. npeAJIOHceH MeTOA OnpeAeJIeHIIR CTPYHTYPbI UeHTpOB peHOM6IIHaUPlki B COeAIJHeHHRX AI1[BV1, OCHOBaHHbIfi Ha COIIOCTaBJIeHHH BbIUleOTMe9eHHbIX 3KCIIepIXMeHTaJIbHblX H TeOPeTH9eCKIIX rpa#HHOB. 3 T O T MeTOA HCTIOJIb30BaH &JIR YCTaHOB-JIeHMR IIpIIpOlZbI r-H k-qeHTpOB (Amax = 1030 n m 13 Amax = 780 nm, COOTBeTCTBeHHO) H S-UeHTpOB 6e3bI3JIyYaTeJlbHOn peKOM6IIHa~IIPl, a TaKXe nOMIIHEiPYlOUHX ne@e€CTOB C1 II Cu B CdS:Cu:Cl. I-, k-II S-IleHTPbI MOrYT 6bITb IIAeHTII@HUIIpOBaHbI CO CJIeAyIoIq-IIMII He@eKTaMH KpIICTaJIJIIIYeCKOfi PeIIIeTKH CdS : -r-UeHTp -(CUCdCls), k-UeHTp -(CUcd);, OAHOBpeMeHHO II ~OMIIHl3pylOUIIMII ne@eKTaMH CU II c1 IIpH COOTBeTCTBYIoIqL2X COOTHOILIe-HIIRX Ncu II Ncl. KOTOPbIX K B~~I I X H M I I Y~C K~R Teopm ne@eIcTOO6pa30BaHHR B TsepnbIx Teaax ~~I I B O~H T s-uemp -(CuCdCui)z n p~ Ncu > Ncl II Cls n p~ Ncu < Nc1. llocnenme m a O K~~~J I M C~ 1) Ehitajate tee 5, 200026 Tallin, USSR. 27'

The structure of recombination centres in activated ZnSe phosphors

“…Intensity of r-and kemission bands @,k depends on the concentration of copper Ncu as a power function with power index in the region -1 5 ~t 5 1, as can be seen from bine through the non-radiative s-channel. According to [28] in such a case, @r,k depends on the concentration of r-, k-, and s-centres, i?r,k,s, i.e.…”

“…Tables 1 and 2 list the values of B for various approximations of the neutrality condition and Cu or C1 material balance, calculated in the same way as in [28]. As can be seen in Fig.…”

Thermodynamicmodelling of Electronic Materials

“…Thus, it became possible to determine the chemical nature of radiative and non-radiative recombination centres and also the chemical nature of the predominant impurities and charged defects at low temperatures. As a result the defect structures of CdS:Cu:CI, ZnSe:Cu:Cl, ZnS:Cu:CI, CdS:Ag:CI, and CulnSe, were established [ll, [13][14][15][16].…”