Synthesis and optical properties of ZnTe1−xOx highly mismatched alloys for intermediate band solar cells

Highly mismatched ZnTe
_1-x
O
_x
(ZnTeO) alloys have been grown by molecular beam epitaxy. X-ray diffraction (XRD) analyses showed that a single-phase ZnTeO layer were grown with a substitutional O composition x up to 1.34% on ZnTe(001) substrate in this experiments. Optical transitions associated with the lower (E
_-
) and upper (E
₊
) conduction subbands resulting from the anticrossing interaction between the localized O states and the extended conduction states of ZnTe were clearly observed, and the dependence of the energy position of these bands on the O composition was consistent with the band anticrossing model. The photovoltaic activities of solar cells using ZnTeO layers are also reported.