| AVS 60th International Symposium and Exhibition | |
| Electronic Materials and Processing | Thursday Sessions |
| Session EM2-ThA |
| Session: | Non-traditional Inorganic Semiconductors |
| Presenter: | K. Kash, Case Western Reserve University |
| Authors: | K. Kash, Case Western Reserve University P. Quayle, Case Western Reserve University E. Blanton, Case Western Reserve University |
| Correspondent: | Click to Email |
The Zn-IV-nitrides, Zn(Si,Ge,Sn)N2, form a family of three ternary semiconductors that, although closely related to the III-nitrides AlN, GaN and InN, have elicited relatively little interest until recently. One reason is surely the great success of the III-nitrides as optoelectronic materials. In addition, while the two higher-bandgap members of the family, ZnSiN2 and ZnGeN2, were first synthesized over four decades ago, it was not until the last couple of years that ZnSnN2, the low-bandgap analogue to InN, was reported. Further investigation of these materials has several motivations, including the promise of strategies for circumventing some of the lingering problems associated with the III-V materials, as well as predictions of interesting properties that are markedly different, in potentially useful ways, from those of the III-V materials. In this talk, we will describe the results of vapor-liquid-solid growth of ZnGeN2 and ZnSnN2, using either ammonia or plasma-activated nitrogen as the nitrogen source. These growth methods have produced high quality polycrystalline material that has made possible the investigation of some of the fundamental properties of these materials, including precise experimental determinations of their band gaps. The investigations have also yielded information relevant to the phase diagrams of the Zn-IV-N systems. In particular, conditions under which Zn3N4, Sn3N2, or ZnSnN2, separately, are produced, have been defined. Finally, the characteristic Raman spectra of both ZnSnN2 and ZnGeN2 show evidence of varying degrees of phonon localization that correlate with the occurrence of “exchange defects”; that is, the exchange of ions between the group II and group IV sublattices, detected through their influence on the x-ray diffraction spectra. For ZnGeN2, we show that the degree of II-IV sublattice disorder--the density of these exchange defects--can be controlled via the choice of growth conditions.
This work was done in collaboration with Jie Shan, Keliang He, Hongping Zhao and Lu Han.