Eective mass and bandstructure of n-InAs from magnetophonon resonance and Raman scattering at temperatures between T  64 and 360 K 1 D. Schneider a, * , C. Brink a , G. Irmer b , P. Verma b a Institut f  ur Technische Physik und Hochmagnetfeldanlage, Technische Universit  at Braunschweig, Mendelssohnstr. 2, D-38106 Braunschweig, Germany b Institut f  ur Theoretische Physik, TU Bergakademie Freiberg, Bernhard-von Cotta-Str. 4, D-09596 Freiberg, Germany Abstract We investigate properties of electrons and phonons in n-InAs and their interaction by the magnetophonon resonance (MPR) at temperatures between T  64 K and for the ®rst time to above room temperature. Raman scattering exper- iments were performed to determine the frequency of longitudinal optic phonons, also for the ®rst time over the whole range from T  77 to 400 K. The transversal magnetoresistance was measured at more than ®fty dierent temperatures between T  64 and 360 K. We observed MP oscillations and extract the fundamental resonance ®eld B 0 (T) for the ®rst time for InAs by a full curve ®t of the formula for MPR, derived by Barker. We deduce the eective bandedge mass of electrons m  0 (T), consider nonparabolicity as well as polaron eect and compare it to three and ®ve band kp-calcula- tions. Ó 1998 Elsevier Science B.V. All rights reserved. Keywords: InAs; Eective electron mass; LO-phonon frequency; Raman scattering; Magnetophonon resonance 1. Introduction The III/V-compound semiconductor indium arsenide (InAs) has attracted interest recently (see e.g. [1]) for application in semiconductor hetero- and nanostructures because of its small energy gap and high electron mobility. InAs is also used as a component for ``bandgap engineering'' by growing mixed crystals. Detailed knowledge of its electron eective mass, bandstructure and phonon frequencies at room temperature is important. Due to the nonparabolicity of the conduction band C c 6 , the ``bare'' eective mass m  0 of electrons at the band edge depends on temperature T. This has been deduced for InAs at 110 6 T 6 290 K and 150 6 T 6 250 K experimentally from magnetopho- non resonance (MPR) by Stradling and Wood [2] and Takayama et al. [3], respectively. A review on MPR in InAs is given by Firsov et al. [4]. Those ear- ly results for m  0 (T) deviate from each other as well as from kp-band calculations and were deduced without detailed knowledge of the involved longi- tudinal optical (LO) phonon frequency x LO (T) over the whole temperature range. We investigate n-InAs by a procedure similar to the one used in the latest MPR investigations of n-InP [5] and n- GaAs [6]. The evaluated m  0 (T) is compared to three [7] and ®ve band [8] kp-calculations. Physica B 256±258 (1998) 625±628 * Corresponding author. Fax: 49 531 391 5504; e-mail: d.schneider@tu-bs.de 1 Dedicated to Prof. Dr. Andreas Schlachetzki, TU Braunschweig, Germany, on the occasion of his 60th Birthday. 0921-4526/98/$ ± see front matter Ó 1998 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 1 - 4 5 2 6 ( 9 8 ) 0 0 6 8 5 - 1