Local vibrational modes of interstitial boron–interstitial oxygen complex in silicon

Abstract

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.In the present work, we report local vibrational mode (LVM) related absorption lines which are assigned to the complex incorporating interstitial boron and interstitial oxygen atoms (B i O i ), a possible precursor of the center responsible for lightinduced degradation (LID) in solar cells produced from boron-doped oxygen-rich silicon. Fourier transform infrared absorption (IR) spectroscopy was used for detection and analysis of absorption lines due to defects which were created in boron-doped Czochralski-grown Si samples by irradiation with 6 or 10 MeV electrons at room temperature. Changes in the IR absorption spectra upon isochronal annealing of the irradiated samples in the temperature range 75-225 8C have also been monitored. A set of previously unreported LVM lines with the same formation and elimination behavior has been studied. The most intense lines of the set are found to be at 991, 721, and 550 cm À1 . On the basis of an analysis of changes in intensity of the lines with the concentrations of impurities in the silicon and on the similarity of their annealing features with those for the DLTS signal due to the B i O i center, it is argued that the lines are related to the LVMs of this defect. The positions of the lines have been compared with the previously reported LVMs derived from ab initio modeling calculations for different configurations of the B i O i complex. A configuration having calculated LVMs close to those determined experimentally has been found and the origins of the modes are discussed.

Electronic absorption of interstitial boron‐related defects in silicon

“…In the previous studies , it was shown by DLTS that the B i C s complexes in boron‐doped Cz‐Si arise synchronously with the dissociation of B i O i defects. The annealing temperature for B i O i , according to the studies is 150–200 °C, i.e., slightly higher than that for B i B s defects observed by us. Taking into account the closeness of these two annealing processes, it can be concluded that B i atoms liberated as a result of the dissociation of both B i B s and B i O i are involved in the formation of B i C s defects in the oxygen‐rich material.…”

“…Therefore, the interpretation of the observed bands requires additional studies. The set of LVMs at 991, 721, and 550 cm ­−1 in work is associated with B i O i ‐related defects. In a recent study , the absorption bands at 739.4, 759.6, and 780.9 cm ­−1 were identified as LVMs associated with B i B i defects, and the line at 923.5 cm ­−1 was ascribed to the complexes involving interstitial boron and interstitial oxygen atoms.…”

Features of the Formation of the BiBs Defect in Si

“…[7,21] A new set of absorption bands positioned at about 538, 550, 688, 721, 756, and 991 cm À1 was identified as LVMs of the B i O i complex. [22] The studies performed by deep-level transient spectroscopy and electron paramagnetic resonance methods indicate that, at the injection of minority carriers, a significant increase in the rate of annealing of B i can be observed in accordance with the Bourgoin-Corbett mechanism. [4,23] Recently, it was shown that the enhanced diffusion of interstitial boron can occur also during the irradiation of samples at a temperature of 80 K. [24,25] The absorption spectra of the as-irradiated samples contain no LVMs associated with interstitial boron, but the LVMs of defects, whose composition includes interstitial boron, were registered.…”

“…Two LVMs at 733 and 760 cm –1 were assigned to the B i B s complex . A new set of absorption bands positioned at about 538, 550, 688, 721, 756, and 991 cm −1 was identified as LVMs of the B i O i complex …”

Dephasing Dynamics across Different Local Vibrational Modes and Crystalline Environments

“…Rather than ignoring or filtering away PFID as a "coherent artifact" of pump-probe measurements [28], PFID may serve as a powerful tool in optics and ultrafast spectroscopy by providing subtle features that, when modeled accurately, yield accurate dephasing rates. These advances will be of interest in (i) chemical physics, where PFID as a spectroscopic technique is widely applicable to study the ultrafast vibrational dynamics of solidstate, liquid-phase, and gas-phase molecular systems [20][21][22][23][24][25][26][27]; (ii) molecular chemistry, where using PFID to accurately measure T 2 across different vibrational modes would advance the molecular design of popular systems such as modified graphene [40] and dye molecules [41], and could also uncover key molecule-environment interactions [42]; and (iii) semiconductor and quantum physics, where PFID may be used to probe defect-lattice interactions within tailored defect environments in diamond, as in the present work, or indeed in other semiconductor materials with important functional defects, such as GaN [43], silicon [44], or metal oxides [45]. The FTIR spectrum of S1 could not be resolved for N 0 s and A=B centers.…”