Abstract
In this paper we describe the results of spectrally resolved photo-resistance investigations of optically induced charge storage in self-assembled InAs quantum dots. The results obtained demonstrate that, following resonant photo-excitation of the dots, excitons can be selectively ionised leaving either electrons or holes stored. This charge is sensed remotely using a density tuneable 2D electron - hole system and is shown to remain stored over very long timescales (>8 hours) at elevated temperature (~150K). By analysing the temporal dependence of the charge storage effect, the optical absorption strength of the quantum dots is estimated to be ~3.5x10-5. The potential operation of the devices investigated as highly sensitive photo-transistors or a basic optical memory element is suggested.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
For example: D. Leonard, M. Krishnamurty, C. M. Reaves, S. P. DenBaars, and P. M. Petroff, Appl. Phys Lett. 63 3203 (1993).
S. Muto. Jpn. J. Appl. Phys. 34 L210 (1995).
L. Zhuang, L. Guo and S.Y. Chou, Appl. Phys. Lett. 72, 1205 (1998).
H. Yusa and H. Sakaki, Appl. Phys. Lett. 70 345 (1997).
K Imamura, Y. Sugiyama, Y. Nakata, S. Muto, and N Yokoyama, Jpn. J. Appl. Phys 34 L1445 (1995).
J.J. Finley, M. Skalitz, M. Arzberger, A. Zrenner, G. Böhm and G. Abstreiter, Appl. Phys. Lett. 73, 2618, (1998).
A. J. Shields, M. P. O’Sullivan, I. Farrer, D. A. Ritchie, K. Cooper, C. L. Foden and M. Pepper, “Optically Induced Bistability in the Mobility of a 2DEG Coupled to a Layer of Quantum Dots” Submitted to Phys. Rev. B (1999).
H. Sakaki, G. Yusa, T. Someya, Y. Ohno, T. Noda, H. Akiyama, Y. Kadoya, and H Noge, Appl. Phys. Lett. 67 3444 (1995).
E. Ribeiro, E. Miller, T. Heinzel, H. Auderset, K. Ensslin, G. Medeiros-Ribeiro, and P M Petroff, Phys. Rev. B58 1506 (1998).
P. W. Fry, I. E. Itskevitch, D. J. Mowbray, M. S. Skolnick, J. A. Barker, E. P. O. O’Reilly, L. R. Wilson, I. A. Larkin, P. A. Maksym, M. Hopkinson, M. Al-Kafaji, J. P. R. David, A. G. Cullis, G. Hill, and J. C. Clarke, Submitted to Phys Rev. Lett.
D. J. Chadi and K. J. Chang, Phys. Rev. Lett. 61 7 873 (1988).
L. Chu, M. Arzberger, G. Böhm and G. Abstreiter, Journal of Applied Physics 85 2355 (1999).
For T<100K, both samples-A and B exhibit an additional persistent photo-response, the contribution of which becomes stronger as the temperature decreases. These effects are completely absent at T=145K, and the observed photo-response arises solely from charge storage in the QD layer.
The samples were typically reset by passing between Ipn=1–10μA for times between 100–300ms.
We note that the form of the excitation cycle for Eex=1059meV is representative of the measured response to higher Ea,, up to 1250meV whilst the Eex 1016meV cycle typifies the lower excitation energy response
S. Raymond, P. J. Poole, S. Fafard, A. Wojs, P. Hawrylak, S. Charbonneau, D. Leonard, P. M. Petroff, and J. L. Merz, Phys. Rev. B54 11548 (1996).
R. J. Warburton, B. T. Miller, C. S. Dürr, C. Bödefeld, K. Karrai, J. P. Kotthaus, G. Medeiros-Ribeiro, P. M. Petroff, and S. Haunt, Phys. Rev. B58 16221 (1998).
Using simple electrostatic arguments, this factor may be related simply to the separation from the 2D electron channel of the dot layer (\( {\ell _1} \) ) and p-contact (\( {\ell _2} \) ) respectively i.e. \( f = {\left( {1 - \frac{{{\ell _2}}}{{{\ell _1}}}} \right)^{ - 1}} \)
For our sample we expect that the n-channel mobility is controlled by optical phonon and ionised impurity scattering at 145K. Furthermore, the QD layer is separated by 50nm from the n-channel and has in ref 8, for a similar structure, been shown not to strongly perturb the channel mobility. Thus, the strongest effect on the channel conductivity is expected to arise from the reduction of the 020.
Using f=0.8 and μ=8000 cm2/Vs.
R. J. Warburton, C. S. Dürr, K. Karrai, J. P. Kotthaus, G. Medeiros-Ribeiro, and P. M. Petroff. Phys Rev. Lett. 79 5282 (1997).
For the electron storage sample, the strength of the observed photoeffect reduces for T>170K, and is not observed for T>230K.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2000 Springer Science+Business Media Dordrecht
About this chapter
Cite this chapter
Heinrich, D. et al. (2000). Optical Charging of Self-Assembled InAs Quantum Dots. In: Sadowski, M.L., Potemski, M., Grynberg, M. (eds) Optical Properties of Semiconductor Nanostructures. NATO Science Series, vol 81. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-4158-1_37
Download citation
DOI: https://doi.org/10.1007/978-94-011-4158-1_37
Publisher Name: Springer, Dordrecht
Print ISBN: 978-0-7923-6317-0
Online ISBN: 978-94-011-4158-1
eBook Packages: Springer Book Archive