Determination of the in-plane mass in strained GaInAs/InP quantum wells

In this paper we present a determination of the valence band structure of strained GaInAs/InP quantum wells by measuring the effective in-plane hole masses. To determine the masses, we performed low temperature magnetotransport measurements (1.5-15 K), magnetoluminescence as well as far infrared transmission spectroscopy. Hole carrier mobilities up to 8700 cm²/Vs were obtained for compressively strained samples with a gallium content of x_Ga=0.3. For compressively strained samples all measurements showed a drastical reduction of the valence band masses compared to both, bulk values and the values of unstrained quantum well structures. Tensile strained samples show, according to an indirect band structure at the cross over of light and heavy hole extremely large effective masses. For increasing tensile strain, the band structure becomes again direct, whereas the effective masses show values which are above those of compressively strained samples. Therefore tensile strained samples could only be analysed qualitatively by magnetoluminescence. All of our observations are in good agreement with k·p-theory. A more precise analysis of the Shubnikov-de Haas oscillations showed a spin splitting of the uppermost valence band in compressively strained quantum well structures, leading to two different effective masses