Compensating acceptors and donors in nitrogen δ-doped ZnSe layers studied by photoluminescence and photoluminescence excitation spectroscopy

Abstract

The compensating acceptors and donors in nitrogen δ-doped ZnSe epilayers grown by molecular beam epitaxy using a nitrogen rf-plasma source are studied by means of photoluminescence (PL) and photoluminescence excitation spectroscopy (PLE). The temperature dependence of PL and PLE spectra obtained from the nitrogen δ-doped layers is investigated in detail, and a deep acceptor and a deep donor with ionization energies of ∼170 and ∼88 meV are reported for the nitrogen δ-doped layers. These two deep centers are assigned to N clusters, i.e., NSe-Zn-NSe for the deep acceptor and NSe-NZn for the deep donor.

p-type doping of (Zn,Mg,Cd)Se alloys using a radio frequency discharge nitrogen plasma source

“…It has been shown that ␦-doping can suppress the complex-type defects in various materials such as in GaAs and ZnSe for either type of doping. [20][21][22] Thus, with the ͑NϩTe͒␦-doping in Zn 1Ϫy Cd y Se and Zn 1Ϫx Mg x Se ternaries, it is reasonable to expect that the complex-type compensation defects should be reduced. Furthermore, the impurity-host bond ͑Mg-N and Cd-N bonds͒ breaking ͑DX-like center defects͒ should be reduced by depositing nitrogen on the Zn-terminated surface.…”

“…Proposed compensation defects with nitrogen doping include: ͑1͒ native defects ͑such as vacancies and interstitials͒, ͑2͒ complex defects consisting of nitrogen combined with a native defect ͑such as N Se -V Se and N Se -Zn i ), ͑3͒ nitride complex defects ͑such as Se 4 N 4 and Cd 3 N 2 ͒, ͑4͒ associated nitrogen compensation centers ͓such as Zn-͑N Se ) n , and N Se -N Zn ͔, and ͑5͒ bond breaking defects ͑DX-like centers, such as impurityhost and host-host bond breaking͒. [7][8][9] In fact, many theoretical and experimental studies in the past years have been devoted to examining which defects dominate the compensation phenomena in ZnSe:N. [10][11][12][13][14] These investigations have led to the conclusion that only some of the proposed compensation defects, such as the N Se -V Se complexes, the nitride complexes and the host-host bond breaking defects, may have a significant effect in ZnSe:N.…”

Compensation introduced by defect complexes in p-type ZnSe

“…This fact is the reason for previous discrepancies. In 1995, a deep acceptor and a deep donor with ionization energies of ϳ170 and ϳ88 meV in heavily N-doped ZnSe were detected by using photoluminescence and photolumine excitation spectroscopy, 14 and it was proposed that they were N clusters, i.e., N Se -Zn-N Se for the deep acceptor and N Se -N Zn for the deep donor, as shown in Fig. 1͑b͒.…”

Enhancement of p-type doping of ZnSe using a modified (N+Te)δ -doping technique

“…Delta doping has been proposed to reduce complex-type defects. [8][9][10] For ZnSe:N, Zhu et al have proposed that the N Se -V Se complex can be suppressed by ␦ doping. 8 Ϫ3 .…”