Ionization energy of acceptors in As-doped HgCdTe grown by molecular beam epitaxy

Abstract

The p-type activation of arsenic (As) in (211)B mercury cadmium telluride (HgCdTe) grown by molecular beam epitaxy (MBE), with different compositions covering the 3–5 and 8–14 μm atmospheric transmission windows and after annealing at 300 °C is reported. The composition and thickness of the MBE layers were determined from Fourier transform infrared transmission measurements at room temperature. The ionization energies of shallow acceptors related to As in MBE HgCdTe layers with different Cd compositions have been obtained by fitting variable temperature Hall measurement results to a two-band nonparabolic Kane model. The results indicate that As incorporated during the MBE growth can be activated to provide a shallow acceptor level in MBE HgCdTe and the ionization energy of the As acceptor decreases with decreasing Cd composition, in agreement with the theory.

Correlation of arsenic incorporation and its electrical activation in MBE HgCdTe

“…[1][2][3] It has been commonly assumed that arsenic is incorporated in MBE growth primarily as isolated atoms even if the source is As 4 . [1][2][3] It has been commonly assumed that arsenic is incorporated in MBE growth primarily as isolated atoms even if the source is As 4 .…”

The bulk generation-recombination processes and the carrier lifetime in mid-wave infrared and long-wave infrared liquid nitrogen cooled HgCdTe alloys

“…Swartz et al 10 have concluded that increasing of carrier lifetime in the heaviest doped samples is caused by trapping states which may be introduced during the incorporation and activation of arsenic. It is hardy to agree with this conclusion, especially if the results of experimental [11][12][13][14][15][16][17][18][19][20][21][22][23] as well as theoretical [24][25][26] works, showing a significant reduction of SRH centers in the As-doped structures annealing in mercury atmosphere, has been examined. To explain these divergences, we re-examine the carrier lifetime in this paper.…”

Arsenic-doped narrow-gap HgCdTe epilayers studied by infrared modulation spectroscopy

“…25 Experimentally, Hall measurements suggested that the ionization energy related to As as an acceptor (As Te ) is less than 10 meV and the energy for mercury vacancy (V Hg ) is about 85 meV for Hg 0.72 Cd 0.28 Te layers. 26 Meanwhile, optical absorption and PL measurements indicated an energy level of V Hg to be about 9~12 meV above the valence-band maximum of HgCdTe. 27,28 The values were contradictory, and the second level of V Hg was not experimentally observed though it was theoretically predicted to be a double-level acceptor.…”