Measurement of modal absorption, gain and recombination in p-doped and intrinsic quantum dot structures

Author

Sandall, I.C. ; Walker, C.L. ; Smowton, P.M. ; Mowbray, D.J. ; Liu, H.Y. ; Hopkinson, M.

Author_Institution

Sch. of Phys. & Astron., Cardiff Univ.

Volume

153

Issue

6

fYear

2006

fDate

12/1/2006 12:00:00 AM

Firstpage

316

Lastpage

320

Abstract

The segmented contact method is used to study the performance of intrinsic and p-doped quantum dot structures emitting at 1.3 mum. From measurements of the absorption, it is shown that despite being doped to a level of 18 acceptor atoms per dot, only 19% of the quantum dot states are filled by excess holes, illustrating the importance of the continuum states in the wetting layer. We directly measure the modal gain and non-radiative recombination and show that the modal gain is increased as a function of transparency point when p-dopants are introduced without a significant increase in non-radiative recombination. These results explain the 65% reduction in threshold current observed for uncoated 1500 mum long devices at 300 K

Keywords

quantum dot lasers; semiconductor doping; semiconductor quantum dots; transparency; 1.3 mum; 1500 mum; 300 K; InAs quantum dot lasers; acceptor atoms; continuum states; excess holes; intrinsic quantum dot; modal absorption; modal gain; nonradiative recombination; p-dopants; p-doped quantum dot; quantum dot states; transparency; wetting layer;

fLanguage

English

Journal_Title

Optoelectronics, IEE Proceedings -

Publisher

iet

ISSN

1350-2433

Type

jour

DOI

10.1049/ip-opt:20060042

Filename

4027856