Ran Guangzhao

Electrically Pumped Room-Temperature Pulsed InGaAsP-Si Hybrid Lasers Based on Metal Bonding

A pulsed InGaAsP-Si hybrid laser is fabricated using metal bonding. A novel structure in which the optical coupling and metal bonding areas are transversely separated is employed to integrate the silicon waveguide with an InGaAsP multi-quantum well distributed feedback structure. When electrically pumped at room temperature, the laser operates with a threshold current density of 2.9 kA/cm(2) and a slope efficiency of 0.02 W/A. The 1542 nm laser output exits mainly from the Si waveguide.

Synthesis and PL Properties of ZnSe Nanowires with Zincblende and Wurtzite Structures

Single crystalline ZnSe nanowires with both zincblende and wurtzite structures have been synthesized via a chemical vapour deposition method under different growth conditions. The nanowires are usually 50–80 nm in diameter, and several tens of microns in length. Room-temperature photoluminescence spectra from zincblende and wurtzite ZnSe nanowires show a broad luminescence band peaked at around 2.71 eV and a deep level emission band peaked at around 2.00 eV, respectively. Effects of post-growth annealing on the photoluminescence of these nanowires have been investigated. Strong room-temperature band-edge emission could be obtained from the annealed zincblende ZnSe nanowires.

Electroluminescence and photoluminescence from scored Si-rich SiO2 film/p-Si structure

Electroluminescence (EL) is observed from the Au/Si-rich SiO2 film/p-Si diodes, in which the Si-rich SiO2 films are scored deliberately by a diamond tip. The EL intensity of the scored diode annealed at 800 degreesC is about 6 times of that of the unscored counterpart. The EL spectrum of the unscored diode could be decomposed into two Gaussian luminescence bands with peaks at about 1.83 and 2.23eV, while for the EL spectrum of the scored diode, an additional Gaussian band at about 3.0eV appears, and the 1.83-eV peak increases significantly in intensity. The photoluminescence (PL) spectrum of an unscored Si-rich SiO2 film has only one band peaking at about 1.48eV, whereas the PL spectrum of the scored one has two bands at about 1.48 and 1.97eV. We consider that the high-density defect regions produced by the scoring provide new luminescence centres and become some types of nonradiative centres in the Si oxide layer, which thus result in changes of the EL and PL spectra.

Photoluminescence characterization of silicon nanoparticles hybridized europium complex

A europium complex Eu (DBM)(3) TPPO (Eu tris(belizoylmethide)-(triphenylphosphine oxide)) and silicon nanoparticles have been hybridized. The hybridization can evidently change the photoluminescence (PL) characteristics of the Eu complex in the following aspects: under an excitation of 390 nm, the intensity of the PL peak at 611 nm due to the D-5(0)-F-7(2) transition of the Eu3+ ions has been increased by 30%, and the integrated PL intensity in the visible range has been increased by nearly 3 times; the PL excitation efficiency beyond 440 nm has been improved evidently; the peak in the PL excitation spectrum shifts from 408 to 388 nm, and the PL decay time decreases from 2.07 to 0.96 mus. The experimental results indicate that in the PL process, the photoexcited energy may transfer from the silicon nanoparticles to the Eu3+ ions.

Photo- and Electro-Luminescence at 1.54 μm from Er3+ in SiC:Er2O3 Films and Structures

SiC:Er2O3 films with different ratios of SiC to SiC:Er2O3 are deposited on p-type Si substrates by the magnetron co-sputtering technique, which was fully compatible with current Si processing technologies. Intense room temperature 1.54 μm photoluminescence (PL) from Er3+ ions in the SiC:Er2O3 films is observed and the PL intensity at 1.54 μm is enhanced by about 40 times with increasing Er concentration in the films from 0.8 to 22 at.% under both direct and indirect excitations. The 1.54 μm electroluminescence from the structure of indium tin oxide (ITO)/n+ -Si/SiC:Er2O3/p-Si with suitable ratios of SiC to SiC:Er2O3 is measured under forward biases.