Tunnel Junction AlGaInP Light Emitting Diode

The n-type GaAs substrates are used and their conductive type is changed to p-type by tunnel junction for AlGaInP light emitting diodes (TJ-LED), then n-type GaP layer is used as current spreading layer. Because resistivity of the n-type GaP is lower than that of p-type, the effect of current spreading layer is enhanced and the light extraction efficiency is increased by the n-type GaP current spreading layer. For TJ-LED with 3μm n-type GaP current spreading layer, experimental results show that compared with conventional LED with p-type GaP current spreading layer, light output power is increased for 50% at 20mA and for 66.7% at 100mA.

Light induced rapid thermal diffusion of boron atom in silicon

国家自然科学基金

Strong red light emission from silicon nanocrystals embedded in SIO2 matrix

In this study, silicon nanocrystals embedded in SiO2 matrix were formed by conventional plasma enhanced chemical vapor deposition (PECVD) followed by high temperature annealing. The formation of silicon nanocrystals (nc-Si), their optical and micro-structural properties were studied using various experimental techniques, including Fourier transform infrared spectroscopy, micro-Raman spectra, high resolution transmission electron microscopy and x-ray photoelectron spectroscopy. Very strong red light emission from silicon nanocrystals at room temperature (RT) was observed. It was found that there is a strong correlation between the PL intensity and the substrate temperature, the oxygen content and the annealing temperature. When the substrate temperature decreases from 250degreesC to RT, the PL intensity increases by two orders of magnitude.

Potential light source for photonic integrated circuits based on the equilateral triangle resonator

The semiconductor microlasers based on the equilateral triangle resonator (ETR) can be fabricated from the edge-emitting laser wafer by dry-etching technique, and the directional emission can be obtained by connecting an output waveguide to one of the vertices of the ETR. We investigate the mode characteristics, especially the mode quality factor, for the ETR with imperfect vertices, which is inevitable in the real technique process. The numerical simulations show that the confined modes can still have a high quality factor in the ETR with imperfect vertices. We can expect that the microlasers is a suitable light source for photonic integrated circuits.