Silicon nanocluster sensitization of erbium ions under low-energy optical excitation

Abstract

Dopant effects on the photoluminescence of interstitial-related centers in ion implanted silicon J. Appl. Phys. 111, 094910 (2012) Above-room-temperature photoluminescence from a strain-compensated Ge/Si0.15Ge0.85 multiple-quantumwell structure Appl. Phys. Lett. 100, 141905 (2012) Capability of photoluminescence for characterization of multi-crystalline silicon J. Appl. Phys. 111, 073504 (2012) Investigation of defect states in heavily dislocated thin silicon films J. Appl. Phys. 111, 053706 (2012) Additional information on J. Appl. Phys. The sensitizing action of amorphous silicon nanoclusters on erbium ions in thin silica films has been studied under low-energy (long wavelength) optical excitation. Profound differences in fast visible and infrared emission dynamics have been found with respect to the high-energy (short wavelength) case. These findings point out to a strong dependence of the energy transfer process on the optical excitation energy. Total inhibition of energy transfer to erbium states higher than the first excited state ( 4 I 13/2 ) has been demonstrated for excitation energy below 1.82 eV (excitation wavelength longer than 680 nm). Direct excitation of erbium ions to the first excited state ( 4 I 13/2 ) has been confirmed to be the dominant energy transfer mechanism over the whole spectral range of optical excitation used (540 nm-680 nm). V C 2012 American Institute of Physics.

Hot-carrier-mediated impact excitation of Er3+ ions in SiO2 sensitized by Si Nanocrystals

“…It has been suggested to be due to a combination of defect-related emission and a fast direct excitation of Er 3þ ions competing with efficient non-radiative processes of energy back transfer from Er 3þ to the NC core. 21,23,24 The second region (b) shows a slower rise, indicating the energy transfer from Si NCs to Er by non-radiative recombination of the e-h pair. The time constant of this rise is determined by the combination of the energy transfer time and the relaxation time from the higher excited states to the 1st excited state of Er.…”

“…determined as function of average number of absorbed photons per NC, as determined following the procedure described in Ref. 23. We note that I T1 is proportional to the population of Er ions that are excited via fast processes.…”

Infrared photoconductivity of Er-doped Si nanoclusters embedded in a slot waveguide

“…1,2,6 The presence of sub-gap states, through which Si nanoclusters sensitize Er ions, is a central point of several models of energy transfer between Si nanoclusters and Er ions. 7,8 Silicon nanoclusters also enable electrical excitation of coupled Er 3þ ions. 1,9 Silicon is a transparent material and a poor photoconductor at 1.5 lm.…”