Photoluminescence investigation of Si as p-type dopant in AlGaAs grown by molecular beam epitaxy on high-index planes

Abstract

A systematic study of AlGaAs doped with Si in a wide doping range and grown on (N 11)A GaAs surfaces (N ≤ 3) by molecular beam epitaxy is reported. The growth conditions have been kept the same for all the surface orientations. Both electrical and photoluminescence measurements have been carried out to investigate the Si incorporation. All the samples display a p-type conductivity indicating that Si incorporates predominantly on the As sites. A lower C incorporation on the (111)A surfaces than on (211)A and (311)A has been found. We observed that the (111)A planes have a lower optical and morphological quality. However, the values of the Hall mobility, of the free carrier concentration and of the photoluminescence efficiency are not degraded. The samples grown on the (311)A planes show a higher optical quality with shallow-impurity-related optical transitions, while in the samples grown on the (211)A planes both crystalline defects and shallow impurities are found. The results are explained in terms of the substrate orientation dependence of the ratio of single to double dangling bonds.

Substrate orientation effect on potential fluctuations in multiquantum wells of GaAs∕AlGaAs

“…In the ͓311͔A orientation, the peak at 1.966 eV is associated with recombination involving donor-to-acceptor pairs ͑D , C͒, in which the donor is not identified. [22][23][24][25] In the ͓311͔B direction, the ͑e , C͒ emission signal is stronger than that seen in ͓311͔A. This behavior is supposedly due to the higher affinity for impurity incorporation in ͓311͔B.…”

The origin of gate hysteresis in p-type Si-doped AlGaAs/GaAs heterostructures

“…The importance of dangling-bond presentation to surface chemistry is well known; for example, it affects the incorporation probability of Si into Al/Ga sites versus As sites during growth. 66 XPS studies show that ammonium sulfide treatment of (100) GaAs surfaces leads to disulfide bridges between adjacent surface As atoms. 62 It would be interesting to investigate whether this changes for the (311) surface; the corresponding effect on surface-state spectrum could be established using deep level transient spectroscopy (DLTS).…”

Photoluminescence Studies of Mg-Doped AlxGa1-xAs Epitaxial Layers Grown by Molecular Beam Epitaxy

“…Investigations of Mg-doped Al x Ga 1Àx As alloys have been devoted to the optical and electrical properties, mainly owing to their technical importance in the fabrication of modern optoelectronic devices. [1][2][3][4][5][6][7] Molecular beam epitaxy (MBE) is a promising technique for the epitaxial growth of semiconductor materials, in which growth results from impinging molecular beams of the constituent elements simultaneously onto a heated substrate. [6][7][8] The growth is governed primarily by kinetics rather than by thermodynamic equilibrium as compared with that of liquid-phase epitaxy of chemical vapor-phase epitaxy.…”