A unique photoemission method to measure semiconductor heterojunction band offsets

作者：Zhang Q^*; Li R; Yan R; Kosel T; Xing H G; Seabaugh A C; Xu K; Kirillov O A; Gundlach D J; Richter C A; Nguyen N V

来源：Applied Physics Letters, 2013, 102(1): 012101.

DOI：10.1063/1.4772979

We report a unique way to measure the energy band offset of a heterojunction by exploiting the light absorption profile in the heterojunction under visible-ultraviolet internal photoemission. This method was used to determine the band alignment of W/Al2O3/n(+)InAs/p(+)Al(0.45)Ga(0.55)Sb heterojunctions that are of interest for tunnel field-effect transistors. The barrier heights from the InAs and Al0.45Ga0.55Sb valence band maxima to the Al2O3 conduction band minimum are found to be 3.24 eV +/- 0.05 eV and 2.79 eV +/- 0.05 eV, respectively, yielding a 0.4 eV +/- 0.1 eV offset at the InAs/AlGaSb interface. This approach can readily be applied to characterize a wide range of other semiconductor heterojunctions.

• 出版日期2013-1-7