Electroreflectance determination of the band profile of ZnSe/n⁺GaAs heterojunction

Abstract

Electrolyte electroreflectance (EER) is used to investigate the interface between undoped ZnSe and heavily n-doped GaAs. The evolution of t h e signal with bias allows an identification of the various features in the EER spectra. The spectra allow u s to determine the band profile of t h e heterojunction, which consists of 100 nm of unintentionally doped ZnSe grown by molecular beam epitaxy on n+GaAs:Si. The band profile that we obtain differs from previously proposed models for the band profile, but explains the transport results that motivated those models. In particular, due to the interdiffusion of Zn and Ga atoms, it displays a strongly p-type region in the GaAs near the interface and an n-type region extending of the order of 5 n m into the ZnSe from the interface.

Anion variations at semiconductor interfaces: ZnSe(100)/GaAs(100) superlattices

“…[12][13][14][15][16][17][18][19][20][21][22][23][24][25] On the free GaAs͑100͒ surface, this ␤2 structure is characterized by two As dimers in the top layer and one Ga dimer vacancy in the second layer that exposes a third As dimer in the third layer. Therefore, it is of practical interest to investigate those interfaces that might reasonably arise from real substrate surface structures.…”