... studyHA1,HA2,HB1,HB3,HC1,HC12 and HD1are acceptorlike traps [11,12].ConclusionIn summary, we studied the effect of different Be -doping concentrations in AlGaAs layers grown on (100) and (311)A GaAs substrates. ... and LDLTS measurements, prepared figures and wrote the first draft. MS, MA, AK and MH participated in the analysis of thedata and the preparation of the manuscript. MH grew the MBE samples and DT ... 6:180http://www.nanoscalereslett.com/content/6/1/180Page 3 of 5compared to those grown on (100) subst rates. Our find-ing is a direct confirmation of their argument.Experimental detailsA set of six AlGaAs samples with different Be -doping concentrations...