R. Sauer

0.79 eV (C line) defect in irradiated oxygen-rich silicon: excited state structure, internal strain and luminescence decay time

Highly excited states of the 0.79 eV luminescent defect observed in photoluminescence excitation (PLE) measurements are interpreted as effective-mass (EMT) states of a pseudo-donor with Ei=38.3 meV. The interpretation implies that the 1s ground state of the donor electron is fivefold split in the C1h symmetric strain field of the defect. Modelling of the internal deformation around the defect by a compressive uniaxial field of 80 MPa along (001) allows the authors to explain the ground state splitting quantitatively and gives rise to a re-interpretation of published uniaxial stress data. Transient decay data suggest that the lowest excited defect state is a split singlet-triplet bound exciton, the 0.79 eV line being emitted by the higher-energy singlet.

Photoluminescence from a thermally induced indium complex in silicon

Abstract A new technique of treating indium doped silicon is described which enhances drastically the luminescence intensities of the long-lived P, Q, R lines. As a consequence, we detect new lines which can consistently be adapted to a level scheme of one center, and by uniaxial stress and magnetic field measurements determine the symmetry of the P, Q, R … line center to be that of a configuration. Arguments are presented that all P line and related luminescence is due to donor-acceptor pair recombination between substitutional indium atoms and iron atoms on next nearest interstitial lattice sites.

Excitons bound to an isoelectronic trap in silicon

Abstract Three novel emission lines in silicon. A, B, and C, are reported which are associated with an exciton bound to an isoelectronic trap. We deduce this interpretation from temperature dependent measurements as well as from Zeeman-, piezo-, and time-resolved spectroscopy. The binding center is assumed to involve carbon.

Optical determination of highly excited s-like donor states in silicon

Abstract Energies of excited s-like donor (P, As, Li) states in silicon are determined from two-electron transition spectra. For the 2 s-state of phosphorus and arsenic the effective-mass-theory is in error by ≈2 meV and becomes successively better for the higher excited states, but agrees satisfactorily with all observed lithium levels. s-like states only are observed for phosphorus and arsenic, but for lithium also p-like states are found, revealing the different ground state symmetries 1s(A 1 ) for P and As or 1s(E + T 1 ) for Li.

Origin of the 1.080 eV (I2) photolumiscence line in irradiated silicon

Abstract We study the 1.080 eV (I 2 ) line in high-resolution photoluminescence and detect an isotope effect which can quantitatively be understood assuming two equivalent boron atoms per optical center. Zeeman measurements indicate that the defect has trigonal symmetry and provide evidence that the line originates from a spin triplet state with g ‖ =2.45 ±0.1,g ⊥ =1.86±0.1 and a zero-field splitting D =(-0.20±0.02)meV. Temperature-controlled measurements and excitation spectroscopy enable us to present an excited states level scheme. The possible local defect structure is discussed.