Intersubband Optical Nonlinearity of GeSn Quantum Dots under Vertical Electric Field.

Mourad Baira,Bassem Salem,Bouraoui Ilahi,Niyaz Ahamad Madhar

doi:10.3390/mi10040243

Abstract

The impact of vertical electrical field on the electron related linear and 3rd order nonlinear optical properties are evaluated numerically for pyramidal GeSn quantum dots with different sizes. The electric field induced electron confining potential profile’s modification is found to alter the transition energies and the transition dipole moment, particularly for larger dot sizes. These variations strongly influence the intersubband photoabsorption coefficients and changes in the refractive index with an increasing tendency of the 3rd order nonlinear component with increasing both quantum dot (QD) size and applied electric field. The results show that intersubband optical properties of GeSn quantum dots can be successively tuned by external polarization.

Highlights

Self-assembled quantum dots have received an increasing interest during the past decades owing to their potentiality for novel optoelectronic devices [1,2]
Recent achievement in direct band gap GeSn material has accentuated its suitability towards comparable properties to III-V materials while being compatible with complementary metal-oxide semiconductor (CMOS) technology [20,21,22,23,24,25]
The present work treats the effect of vertical electric field on intersubband related optical properties of pyramidal GeSn quantum dot (QD) with different sizes for CMOS

Summary

Introduction

Self-assembled quantum dots have received an increasing interest during the past decades owing to their potentiality for novel optoelectronic devices [1,2]. A particular interest has been devoted to the study of linear and nonlinear QD intersubband optical properties [7,9,10,11,12,13,14,15,16,17] for their importance in integrated quantum photonic technologies [18]. Recent achievement in direct band gap GeSn material has accentuated its suitability towards comparable properties to III-V materials while being compatible with complementary metal-oxide semiconductor (CMOS) technology [20,21,22,23,24,25]. The present work treats the effect of vertical electric field on intersubband related optical properties of pyramidal GeSn QD with different sizes for CMOS compatible nonlinear optical devices.

Theoretical Consideration

Results and Discussion

Probability

Conclusions

B.I. Validation