We demonstrate electroluminescence (EL) with an external efficiency of more than 0.1% at room temperature from glide dislocations in silicon. The key to this achievement is a considerable reduction of nonradiative carrier recombination at dislocations due to impurities and core defects by impurity gettering and hydrogen passivation, respectively, which is shown by means of deep-level transient spectroscopy. Time-resolved EL measurements reveal a response time below 1.8 μs, which is much faster, compared to the band-to-band luminescence of bulk silicon.

We investigated correlation between concentration of deep level defects at dislocations, detected by deep level transient spectroscopy (DLTS) and the efficiency of dislocation related luminescence in Si samples with dislocation density of about (3–5) × 108 cm–2. We show that significant reduction of concentration of deep states at dislocations achieved by using the combination of gettering and passivation, results in a drastic (by several orders of magnitude) increase of dislocation‐related D1 luminescence in a high temperature range. As a consequence, electroluminescence (EL) from dislocation related D1‐line reaches an external efficiency more then 0.1% at room temperature. Concentration of D1 and D2 luminescence centers, roughly estimated from the optical absorption spectrum, was found to be of the order of 3 × 1014 cm–3 for dislocation density of about 5 × 108 cm–2. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Photoluminescence bands at 0.778 eV and 0.85 eV are greatly enhanced after low-temperature heat treatment of plastically deformed silicon. Hydrogen passivation of the samples resulted in a reversible distribution of the photoluminescence spectrum, which has been attributed to the passivation of defect levels created during heat treatment. The temperature and doping properties of the emissions suggested that the new emissions originate from electronic transitions between defect levels in the upper half of the energy gap and dislocation-related energy levels. A tentative model of pair recombination between oxygen-related donors and dislocation acceptors has been tested. Using this model and comparing calculated and measured spectra, the energy position of the D1 dislocation acceptor was found to be about 0.36 eV above the valence band.

The dislocation structure and photoluminescence of partially relaxed Si 1−x Ge x layers on Si(001) substrates were studied to reveal the contribution from dislocations localized in different regions of the heterostructure (SiGe layer, SiGe/Si interface, Si substrate) to the dislocation-related PL. The D1 and D2 lines were ascribed to products of dislocation reactions in intersection sites. The known dependence of the D4 line spectral position on the Ge content is not observed, which is explained by the effect of elastic strain in the SiGe/Si heterostructure.

Dislocation related luminescence (DRL) centres in Si have high stability to a thermal treatment of samples and a relatively low temperature quenching. These properties make them an attractive candidate for production of Si based light emitting diodes (LEDs). The low energy part of DRL in the vicinity of the D1 line is the most promising from this point of view due to its highest temperature stability and best coupling to fiber optics. Actually this part of DRL can be divided into several bands. One of them with a position 807 meV is known as D1 line. The substantial effect on D1 luminescence has oxygen. The line becomes broader and several subbands can be identified on the low and high energy side after prolonged annealing of deformed samples. Depending on particular treatment some of these bands could be even more intensive than the original D1 line. The strongest effect is usually observed in oxygen rich CZ crystals. In all cases the presence of dislocations is necessary for the appearance of the low energy bands. Several observations clearly show that the corresponding recombination centres include the dislocation related defect as well as some oxygen complexes. It implies that inclusion and mutual configuration of constituents defines the energy of optical transitions in the region of D1 band. In the present paper a review of previous investigations as well as new results regarding oxygen dislocations interaction are presented.

To prove directly the relation between the emergence of narrow lines in the dislocation photo‐l uminescence spectrum of germanium after the second deformation stage and the splitting value Δ of perfect dislocations a special orientation of crystals at the second deformation stage is used. The samples contain dislocations either with Δ > Δ0 or with Δ < Δ0 (Δ0 is the equilibrium splitting value). The narrow lines are found to arise only on the short‐w ave side of the line corresponding to equilibrium splitting at Δ > Δ0 and on the long‐w ave side at Δ < Δ0. This result and the unique regularity of the narrow line arrangement observed experimentally are considered as a convincing evidence for the effect of the distance between partials on the radiation energy associated with the 90° partials only.

We report the results of a study into the influence of implanted impurities on luminescence in the region of the well-known D1 luminescence band that is associated with dislocations in silicon. A photoluminescence band at around 0.78 eV, which is sometimes seen in silicon containing a high density of dislocations, has been attributed to the presence of oxygen complexes. In this study we have deposited layers of Si 0.9 Ge 0.1 onto single-crystal Si substrates by MBE in order to induce dislocations in the silicon substrate. The samples have subsequently been implanted with iron, erbium or oxygen in order to study the effect of implanted impurities on D-band photoluminescence at around 800 meV. Following implantation with oxygen, two luminescence bands appear at around 0.85 and 0.78 eV, respectively. These bands are not present in either the unimplanted sample or those subject to Er or Fe implantation. The correlation between oxygen doping and the appearance of these bands supports the conjecture that they are associated with oxygen complexes.

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