Properties of reactively sputtered ZnTe:N and its use in recombination junctions

Abstract

Reactively sputtered ZnTe:N is a close valence-band match to CdTe, transparent below 2.2 eV and therefore an attractive candidate for a back contact/tunnel junction in tandem cells using CdTe or CdZnTe top cells. We report on measurements of the optical emission spectra of N/sub 2/ during reactive sputtering as part of the doping optimization. For materials characterization, a series of films produced with various N/sub 2//Ar gas ratios were studied by x-ray diffraction (XRD), atomic force microscopy (AFM), Raman spectroscopy, optical absorption, variable angle spectroscopic ellipsometry (VASE), and the Hall effect. For transparent back contact fabrication, we used a ZnTe:N/ZnO:Al recombination junction bilayer.