Journalartikel

Jahr der Veröffentlichung: 1999

Seiten: 1039-1047

Zeitschrift: physica status solidi (b) – basic solid state physics

Bandnummer: 216

Heftnummer: 2

ISSN: 0370-1972

Verlag: Wiley

Abstract: 
We studied high purity GaAs grown by optically detected cyclotron resonance (ODCR) using microwave frequencies at 36 and 140 GHz. The samples were grown by the metalorganic vapor phase epitaxy (MOVPE) using nitrogen as a carrier gas. The ODCR linewidth which is a measure of the mobility of the sample is dominated by neutral impurity scattering at low temperatures (<10 K) and acoustic deformation potential scattering at higher temperatures (10 to 30 K). At 2 K we obtain a mobility of about 3 x 10(5) cm(2)/Vs, one of the best values for MOVPE grown GaAs. Upon reduction of the photoexcitation power, i.e. reducing the photo-neutralisation of impurities, ionized impurity scattering gives an additional contribution. At high microwave powers the ODCR properties change remarkably, and hot electron relaxation involving longitudinal optical phonon processes is observed.