Photoluminescence study of the one-dimensional material ZrS3 and its solid solution Zr1-xHfxS3

The study of photoluminescence band-tail-localized excitons in ZrS3 and in its solid solution Zr1-xHfxS3 confirms the existence of two polytypes for these one-dimensional materials. Fitting of the spectra, with a model proposed by Ouadjaout and Marfaing, associates a density of states proportional to exp[-(epsilon/epsilon(0))(3/2)] and implies both defect and compositional fluctuations. Gap energy, parallel and perpendicular to the chain direction, has been calculated in Zr1-xHfxS3, and its variation with composition x is found to follow a quadratic law.