Excitonic and edge emission in MOCVD-grown epitaxial films and bulk crystal of ZnS

Effect of isotopic mass on the photoluminescence spectra of β zinc sulfide

“…Our spectra in this region resemble those found in natural ZnS doped with I and Na [11,12]. Correspondingly, we have interpreted our 3.690 eV band as arising from a free-to-bound acceptor (e,A 0 ) transition due to its similarity to that found at 3.677 eV in ZnS doped with I and Na measured at 4.2 K [2,11,12]. At present we do not know the nature of the acceptor involved, its binding energy is 13 meV smaller than that reported for a Na acceptor since both the free-to-bound acceptor band and the zero-order DAP peak are shifted by the same amount with respect to previous measurements [11,12].…”

“…In order to obtain other estimates of the S isotopic mass coefficient and to try to understand the large deviation of the sulfur isotopic mass coefficients derived from the two types of excitons, we have analyzed other bands of the spectra appearing at lower energy at 15 K under He-Cd laser excitation (3.81eV). Figure 3 shows the typical spectrum of some ZnS samples in the 3.40-3.75 eV region at 15 K. In this energy range the spectra of some samples is dominated by a band around 3.690 eV and donoracceptor pair (DAP) transitions with LO phonon-related replicas whose zero-order peak is around 3.626 eV [11]. Our spectra in this region resemble those found in natural ZnS doped with I and Na [11,12].…”

“…Figure 3 shows the typical spectrum of some ZnS samples in the 3.40-3.75 eV region at 15 K. In this energy range the spectra of some samples is dominated by a band around 3.690 eV and donoracceptor pair (DAP) transitions with LO phonon-related replicas whose zero-order peak is around 3.626 eV [11]. Our spectra in this region resemble those found in natural ZnS doped with I and Na [11,12]. Correspondingly, we have interpreted our 3.690 eV band as arising from a free-to-bound acceptor (e,A 0 ) transition due to its similarity to that found at 3.677 eV in ZnS doped with I and Na measured at 4.2 K [2,11,12].…”

High temperature growth of ZnS and ZnMgS by molecular beam epitaxy under high sulfur beam pressure

“…The emis-sion line at 3.789 eV for T sub ϭ410°C, is attributed to excitons bound to neutral donor, (D 0 ,X), according to Ref. 24 where (D 0 ,X) line appeared at 3.790 eV. Deep level emission, not shown here, is weak, especially for T sub ϭ410°C.…”

“…3͑c͒, an emission line located at 3.741-3.743 eV is seen. This line is observed from undoped ZnS grown by various growth techniques, [12][13][14]16,24 and has been attributed to recombination of excitons bound to neutral acceptors, (A 0 ,X). 24 At the lower energy side of this line, a few lines appear under higher excitation power density as shown in Fig.…”