Lattice distortion around impurity atoms as dopants in CdTe

Experimental Verification of Calculated Lattice Relaxations Around Impurities in CdTE

“…A first EXAFS analysis yields a bond length which is in fair accordance with the bond length derived in the WIEN calculation in reproducing the measured EFG at Cd with one Br neighbor in the Te nearest neighbor shell (see Tab.1) (the preliminary result was already presented at the E-MRS Spring Meeting 2004 [14]). However, compared to the perfect agreement obtained for the cases As and Se (within much less than 1%), the analysis seems to be questionable.…”

“…In the XANES region, the model absorption spectra are very similar for both, the substitutional Br and the Acenter Br, resp., however it would be very different for a differently charged Br, for which an illustration was presented already in ref. [14]. There is a clear trend that the XANES spectrum corresponds mainly to positively charged Br configurations.…”

Size dependence of nanostructures: Impact of bond order deficiency

“…Evidence of phase changes occurring at the surface of droplets but not in the bulk for n-alkane emulsions suggests that the phase changes result from the formation of a monolayer thick solid solution of the oil phase [106]. A substitutional As dopant impurity has induced 8% bond contraction around the impurity (acceptor dopant As) at the Te sublattice in CdTe, as observed using EX-AFS (extended X-ray absorption fine structure) and XANES (X-ray absorption near edge spectroscopy) [107]. The finding of dopant-induced bond contraction could provide an atomic scale understanding of the bond in a junction interface that has been a puzzle for decades.…”

Compounds and Nanocomposites: Hetero-Coordination

“…12.2 shows that bond contraction takes place at sites surrounding impurities and at the interfaces. For instances, a substitutional As dopant impurity has induced an 8 % bond contraction around the impurity (acceptor dopant As) at the Te sublattice in CdTe, as observed using EXAFS and XANES [46]. A 3 % Ti-N bond contraction occurs at the TiN/Si 3 N 4 interface [47], being responsible for the hardening of the crystalline/amorphous TiN/Si 3 N 4 multi-layer films.…”

“…14.3(i) has led to a c value of 1.8, indicating that an interfacial bond is 80 % stronger than a bond in the bulk of the core material [64]. If one took the bond contraction to be 0.90-0.92 as determined from the As-and Bi-doped CdTe compound [46] into consideration, the m value is around 5.5-7.0.…”