
Si-Rich $\hbox{Si}_{\rm x}\hbox{C}_{1 - {\rm x}}$ Light-Emitting Diodes With Buried Si Quantum Dots
Author(s) -
Chih-Hsien Cheng,
Chung-Lun Wu,
Chun-Chieh Chen,
Ling-Hsuan Tsai,
Yung-Hsiang Lin,
Gong-Ru Lin
Publication year - 2012
Publication title -
ieee photonics journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.725
H-Index - 73
eISSN - 1943-0655
pISSN - 1943-0647
DOI - 10.1109/jphot.2012.2215917
Subject(s) - engineered materials, dielectrics and plasmas , photonics and electrooptics
The nonstoichiometric ITO/n-SiC/i-SiC/p-Si/Al light-emitting diodes (LEDs) with dense Si quantum dots (Si-QDs) embedded in the Si-rich SixC1-x -based i-SiC layer are demonstrated. The Si-rich SixC1-x films with buried Si-QDs are grown by the plasma-enhanced chemical vapor deposition with varying substrate temperatures. After the annealing process, the average Si-QD size in the Si-rich Si0.52C0.48 film is 2.7 ± 0.4 nm with a corresponding volume density of 1.43 × 1018 cm-3. By increasing the deposition temperatures from 300°C to 650°C, the turn-on voltage and turn-on current of the ITO/n-SiC/i-SiC/p-Si/Al LEDs are found to decrease from 13 to 4.2 V and from 0.63 to 0.34 mA, respectively. In addition, these Si-rich SixC1-x LEDs provide the maximal electroluminescent (EL) power intensity increasing from 1.1 to 4.5 μW/cm2. The yellow (at 570 nm) EL emission power of the ITO/n-SiC/i-SiC/p-Si/Al LEDs reveals a saturated phenomenon due to the Auger effect. The dissipated energy by the lattice thermal vibration contributes to a decayed EL emission power at higher biased currents. The corresponding power-current slope is observed to enhance from 0.45 to 0.61 μW/A with the substrate temperature increasing to 650°C.