abstract

Application of photo- and contactless electro-reflectance
spectroscopies to low dimensional near infrared device structures
J. Misiewicz
Institute of Physics, Wroclaw University of Technology
Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland
Modulation spectroscopy, i.e. photoreflectance (PR) and contactless
electroreflectance (CER), is one of powerful tools to investigate optical properties
of semiconductor systems. The derivative nature of this experimental method
enables observation of a large number of sharp spectral features including those
related to excited state transitions in low-dimensional structures, in contrast to
common emission-type experiments such as photoluminescence (PL), which
usually probes only the ground state. PR and CER spectroscopies are particularly
useful because they are performed in contactless mode that is nondestructive for
samples. In addition, these techniques are very sensitive at room temperature that
it is very important aspect of material characterization since devices normally
operate around room temperature. In this presentation measurement aspects as
well as optical properties of III-V-N quantum wells and InAs based quantum dots
will be discussed. PR and CER techniques will be compared. For example it will
be shown that CER spectroscopy is free of low energy oscillations typical of PR
spectra obtained for samples grown on n-type substrate. In the case of the optical
properties of III-V-N systems following issues will be presented [1-5]. i) Energy
level structure in GaInNAs/GaAs, GaNAsSb/GaAs, and GaInNAsSb/GaAs single
quantum wells (QWs): the band offset and the electron effective mass
determination; ii) energy level structure in step-like GaInNAs/Ga(In)NAs/GaAs,
and GaInNAsSb/GaNAs/GaAs QWs iii) temperature dependence of the band gap
energy in GaNAs, GaInNAs, and GaNAsSb compounds iv) investigation of the
effect of post-growth annealing in PR and CER (absorption-type techniques) vs.
photoluminescence (emission-type technique) v) probing of the different nitrogen
nearest-neighbor environments in GaInNAs compound and GaInNAs/GaAs QWs.
Moreover, the investigations of InAs/GaAs and InAs/InP QD and quantum dash
structures will be presented [6-8].
[1] R. Kudrawiec, P. Sitarek, J. Misiewicz, S.R. Bank, H.B. Yuen, M.A. Wistey, and J.S. Harris Jr,
Appl. Phys. Lett. 86, 091115 (2005).
[2] R. Kudrawiec, K. Ryczko, J. Misiewicz, H.B. Yuen, S.R. Bank, M.A. Wistey, H.P. Bae, and
J.S. Harris Jr, Appl. Phys. Lett. 86, 141908 (2005).
[3] R. Kudrawiec, H.B. Yuen, K. Ryczko, J. Misiewicz, S.R. Bank, M.A. Wistey, H.P. Bae, and
J.S. Harris Jr, J. Appl. Phys. 97, 053515 (2005).
[4] J. Misiewicz, R. Kudrawiec, K. Ryczko, G. Sęk, A. Forchel, J.C. Harmand, and M. Hammar, J.
Phys.: Condens. Mat. 16, 3071 (2004).
[5] R. Kudrawiec, G. Sek, J. Misiewicz, L.H. Li, and J.C. Harmand, Appl. Phys. Lett. 83, 1379
(2003).
[6] W. Rudno-Rudzinski, K. Ryczko, G. Sek, J. Misiewicz, M.J. da Silva, and A.A. Quivy, Solid
State Commun. in press (2005).
[7] W. Rudno-Rudziński, G. Sęk, K. Ryczko, R. Kudrawiec, J. Misiewicz, A. Somers, R.
Schwertberger, J. P. Reithmaier, and A. Forchel, Appl. Phys. Lett. 86, 101904 (2005).
[8] P. Podemski, G. Sek, K. Ryczko, J. Misiewicz, B. Alloing, L.H. Li, and A. Fiore, Appl. Phys.
Lett. submitted (2005).