Properties of the As-related shallow acceptor level in heteroepitaxial ZnSe grown by molecular-beam epitaxy

Yong-Hang Zhang, Brian Skromme, S. M. Shibli, M. C. Tamargo

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


The As-related shallow acceptor level in ZnSe is characterized in detail by low- and variable-temperature photoluminescence (PL), selective-pair luminescence, and magnetospectroscopy measurements, using intentionally As-doped material grown by molecular-beam epitaxy on GaAs. The shallow-acceptor-related PL features grow progressively stronger with Zn3As2 flux, while deep-level peaks at 2.20 and 1.7 eV are observed only at the highest doping levels. In addition to the previously reported donor-to-acceptor peak at about 2.693-2.697 eV, we observe a corresponding band-to-acceptor peak at temperatures of ∼25 K and above. The temperature dependence of the band-acceptor peak position yields a light-hole-acceptor binding energy of 114.6±0.7 meV for thermally strained material, which compares to values of 114.1±0.4 and 113.0±0.6 meV we recently obtained in the same way for Li and N acceptors, respectively. The corresponding value for unstrained material is calculated to be EAAs=114.8±0.7 meV. Selective pair luminescence is used to study the excited states. Four states are observed and assigned to the 2p3/2, 2s3/2, 2p5/2 (Γ7), and 3s3/2 levels, respectively. These levels lie about 73.6, 83.9, 93.5, and 98.4 meV above the ground state, respectively, which agrees with calculations based on effective-mass theory. In the excitonic region, the previously reported As acceptor-bound exciton peak at 2.7888 eV is found to exhibit a high energy component at 2.7903 eV. The observed splitting, which is similar to that of other shallow acceptor-bound excitons in relaxed heteroepitaxial layers, is modeled by a calculation of the effects due to thermal mismatch strain. The splitting of the acceptor-bound exciton is studied in magnetic fields up to 12 T as a function of orientation. The results suggest that the As-related acceptor has the point symmetry of the lattice, implying that it may involve a simple substitutional acceptor involving As on the Se site. The results imply that the failure to obtain p-type conductivity to date with this dopant is not due to the nonexistence of a suitable shallow level. Further work is necessary to investigate improved incorporation methods and to determine if the shallow level is metastable with respect to lattice distortion.

Original languageEnglish (US)
Pages (from-to)10885-10892
Number of pages8
JournalPhysical Review B
Issue number15
StatePublished - 1993

ASJC Scopus subject areas

  • Condensed Matter Physics


Dive into the research topics of 'Properties of the As-related shallow acceptor level in heteroepitaxial ZnSe grown by molecular-beam epitaxy'. Together they form a unique fingerprint.

Cite this