Electroluminescence Characteristics of Si/SiGe Superlattice
Date Issued
2004
Date
2004
Author(s)
Chen, Kuan-Ting
DOI
en-US
Abstract
The advantage of the optoelectronic component of silicon germanium is fully compatible with the Si-based microelectronic chips. In addition, the progress of the growth techniques for quantum heterojunction structure is in advanced. So the heterojunction structure of silicon germanium is studied far and wide in recent years. In this thesis, the light-emitting diodes (LEDs) with multi-periods of Si/SiGe superlattice operating at room temperature for 1.3-1.4μm emission wavelength are reported.
We design a series of different period number Si/SiGe superlattice structures that is grown by UHV/CVD system in this thesis. Then we analyze the influences of period number of Si/SiGe superlattice on electroluminescence characteristics, especially the electroluminescence (EL) spectra. According to experimental result, the emission intensity from SL is enhanced with increasing period number. In addition, because the depletion region covers all the P-type lightly doped region, so the minority carriers (electrons) will go through the active region and diffuse into P-type heavily doped region (capping layer). Then, electrons will recombine with holes and emit the light of Si wavelength at room temperature. However, at low temperature, the more layer superlattice provides the enough quantum wells to capture injection holes and its stronger confinement causes the higher radiative and nonradiative recombination rate. So that will emit the light of superlattice structure wavelength only.
At another part, we compare the luminescence intensity between the Si/SiGe superlattice and Ge quantum dots. Although the quantum dot offers 3D-confinement and its trap density is smaller than superlattice, but its distribution density is small and causes the luminescense area is smaller than Si/SiGe superlattice. Therefore, the luminescence intensity of Ge quantum dots is weaker than Si/SiGe superlattice. But if we can increase the distribution density of Ge quantum dots, its luminescence intensity can be strengthen.
Subjects
矽鍺
超晶格
矽
電激發光
SiGe
Si
Electroluminescence
Superlattice
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-93-R91943029-1.pdf
Size
23.31 KB
Format
Adobe PDF
Checksum
(MD5):7fee0b75b5e6719640598f8d9746ba1a