Stacking Fault Energy of Si Nanocrystals Embedded in SiO2

Y Q Wang,W S Liang,G G Ross

doi:10.5402/2011/639714

Abstract

Si nanocrystals (Si nc) were produced by the implantation of Si+ into a SiO2 film on (100) Si, followed by high-temperature annealing. High-resolution transmission electron microscopy (HRTEM) observation has shown that a perfect dislocation (Burgers vector b=(1/2)〈110〉) can dissociate into two Shockley partials (Burgers vector b=(1/6)〈112〉) bounding a strip of stacking faults (SFs). The width of the SFs has been determined from the HRTEM image, and the stacking fault energy for Si nc has been calculated. The stacking fault energy for Si nc is compared with that for bulk Si, and the formation probability of defects in Si nc is also discussed. The results will shed a light on the dissociation of dislocations in nanoparticles.

Highlights

Si nanocrystals (Si nc) embedded in a SiO2 matrix have attracted much attention as a promising candidate for optoelectronics. It has been agreed by most researchers that the defect center at the Si nc/SiO2 interface plays an important role in the light emission [1, 2]
High-resolution transmission electron microscopy (HRTEM) observations were performed using a JEOL JEM 2100F transmission electron microscope operating at 200 kV
Extensive HRTEM observations of the Si nc show that a perfect dislocation can dissociate into two Shockley partials (Burgers vector b = (1/6) 112 ) bounding a strip of stacking faults (SFs)

Summary

Introduction

Si nanocrystals (Si nc) embedded in a SiO2 matrix have attracted much attention as a promising candidate for optoelectronics. It has been agreed by most researchers that the defect center at the Si nc/SiO2 interface plays an important role in the light emission [1, 2]. When analyzing the reasons for the formation of defects in the nanocrystals, the following two factors are usually considered [3]: the size effect and the energy of formation of stacking faults (SFs). The probability of defects, for example, SFs, being formed depends on their energy of formation. The influence of stacking fault energy on the formation of defects in Si nc has not been reported yet

Experimental

Results and Discussion

Conclusions