Transmission in symmetrical GaAs/AlxGa1-xAs double-barriers with compositionally nonabrupt interfaces

✍ Scribed by R.R.L. de Carvalho; V.N. Freire; M.M. Auto; G.A. Farias

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 245 KB
• Volume: 15
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1994.1041

✦ Synopsis

Transmission properties of electrons through (\mathrm{GaAs} / \mathrm{Al}{x} \mathrm{Ga}{1-x}) As symmetrical double-barriers with abrupt and nonabrupt interfaces are calculated and compared. The interface potential and carrier effective-mass are obtained assuming a linear variation of the aluminium molar fraction in the transition regions (\mathrm{GaAs} \Leftrightarrow \mathrm{Al}{x} \mathrm{Ga}{1-x}) As. When the electron energy (E_{0,-1, \mathrm{e}}) is smaller than the double-barrier height (V_{x 0}), changes in the internal interfaces widths shift tunneling resonances, while changes in the external interfaces increase the energy widths of the resonant transmission peaks. When (E_{0,-1, e}>V_{x 0}), both external and internal interfaces modify remarkably the transmission of nonabrupt (\mathrm{GaAs} / \mathrm{Al}{x} \mathrm{Ga}{1-x} \mathrm{As}) double-barriers when compared with the abrupt double-barrier, even if their widths are as small as two GaAs lattice parameters. However, the first transmission peaks of abrupt and nonabrupt (\mathrm{GaAs} / \mathrm{Al}{x} \mathrm{Ga}{1-\text { I }}) As double-barriers are very similar, except when the interface widths are greater than four lattice parameters.