Growth rate and surfactant-assisted enhancements of rare-earth arsenide InGaAs nanocomposites for terahertz generation

R Salas,V D Dasika,S D Sifferman,E M Krivoy,M L Lee,D Jung,K M Mcnicholas,S R Bank,S Guchhait

doi:10.1063/1.4991589

Abstract

We report the effects of the growth rate on the properties of iii-v nanocomposites containing rare-earth-monopnictide nanoparticles. In particular, the beneficial effects of surfactant-assisted growth of LuAs:In0.53Ga0.47As nanocomposites were found to be most profound at reduced LuAs growth rates. Substantial enhancement in the electrical and optical properties that are beneficial for ultrafast photoconductors was observed and is attributed to the higher structural quality of the InGaAs matrix in this new growth regime. The combined enhancements enabled a >50% increase in the amount of LuAs that could be grown without degrading the quality of the InGaAs overgrowth. Dark resistivity increased by ∼25× while maintaining carrier mobilities over 3000 cm2/V s; carrier lifetimes were reduced by >2×, even at high depositions of LuAs. The combined growth rate and surfactant enhancements offer a previously unexplored regime to enable high-performance fast photoconductors that may be integrated with telecom compone...

Highlights

While continued efforts to increase output powers beyond the microwatt range have resulted in considerable progress in optical and RF solid state THz emitters,[6,7,8,9,10,11] these devices remain limited by low output powers and uncertainty in the frequency tunability
ErAs:GaAsBi approach reported by Bomberger et al is a noteworthy advance as these materials exhibited excellent dark resistivity and can be pumped with longer-wavelength sources, though more work is needed to achieve high carrier mobilities at the low growth temperatures that are required for dilute-bismide growth
We report the structural quality, electrical properties, and carrier lifetimes of superlattices containing LuAs nanoparticles embedded in a bismuth surfactant-enhanced InGaAs matrix,[44] grown at various LuAs growth rates

Summary

Introduction

Tunable, room-temperature, continuous-wave terahertz (THz) sources are attractive for numerous potential applications.[1,2,3,4,5] While continued efforts to increase output powers beyond the microwatt range have resulted in considerable progress in optical and RF solid state THz emitters,[6,7,8,9,10,11] these devices remain limited by low output powers and uncertainty in the frequency tunability. (Received 22 June 2017; accepted 1 September 2017; published online 25 September 2017)

Results

Conclusion