Electroluminescence Devices Based on Si Quantum Dots/SiC Multilayers Embedded in PN Junction

X Xu,J Xu,K J Chen,Y Q Cao,W Li,P Lu

doi:10.1109/jphot.2013.2295467

Abstract

We deposited a p-i-n structure device with alternative amorphous Si (a-Si) and amorphous SiC (a-SiC) multilayers as an intrinsic layer in a plasma-enhanced chemical vapor deposition (PECVD) system. A KrF pulsed excimer laser-induced crystallization of a-Si/a-SiC stacked structures was used to prepare Si quantum dots (Si QDs)/SiC multilayers. The formation of Si QDs with an average size of 4 nm was confirmed by Raman spectra, whereas the layered structures were revealed by cross-sectional transmission electron microscopy. Electroluminescence (EL) devices containing Si QDs/SiC multilayers embedded in a p-n junction were fabricated, and the device performance was studied and compared with the reference device without the p-i-n structure. It was found that the turn-on voltage was reduced and that luminescence efficiency was significantly enhanced by using the p-i-n device structure. The recombination mechanism of carriers in a Si-QD-based EL device was also discussed, and the improved device performance can be attributed to the enhanced radiative recombination probability in a p-i-n EL device.

Highlights

A silicon-based light emitter is one of the crucial devices in realizing Si-based monolithic optoelectronic integration, which has the advantages of high speed and low power consumption [1]–[3]
It has been reported that the radiative recombination probability can be significantly enhanced in Si quantum dots (Si QDs) compared with their bulk counterpart due to the enhanced overlapping of electron and hole wave functions in a confined system [10]–[13]
We propose the KrF pulsed excimer laser crystallization technique to prepare Si QDs/SiC MLs embedded in the p-n junction to get a p-i-n EL device structure

Summary

Introduction

A silicon-based light emitter is one of the crucial devices in realizing Si-based monolithic optoelectronic integration, which has the advantages of high speed and low power consumption [1]–[3]. It has been reported that the radiative recombination probability can be significantly enhanced in Si QDs compared with their bulk counterpart due to the enhanced overlapping of electron and hole wave functions in a confined system [10]–[13]. We propose the KrF pulsed excimer laser crystallization technique to prepare Si QDs/SiC MLs embedded in the p-n junction to get a p-i-n EL device structure. The laser crystallization technique can get size-controllable sizes without inducing the series impurities interdiffusion problem as reported in the high-temperature annealing process [16]. The power-low of EL intensity as a function of injunction current indicates that the radiative recombination is enhanced by forming the p-i-n device structure

Device Structures and Experimental Details

Results and Discussion

Conclusion