RESUMO
Vertically aligned ZnO nanorods (NRs) were grown hydrothermally on the wide bandgap (â¼3.86 - 4.04 eV) seed layers (SLs) of grain size â¼162 ± 35 nm, prepared using ball-milled derived ZnO powder. The synthesized ZnO NRs were further decorated with ZnS nanocrystals to achieve a ZnO NR-ZnS core-shell (CS)-like nano-scaffolds by a subsequent hydrothermal synthesis at 70 °C for 1 h. UV-Vis-NIR spectroscopy, x-ray diffractometry (XRD), Raman spectroscopy and Field emission scanning electron microscopy (FESEM) coupled with Energy dispersive x-ray spectroscopy (EDX) analyses confirmed the formation of ZnS atop the vertically aligned ZnO NR arrays of â¼1.79 ± 0.17µm length and â¼165 ± 27 nm diameter. Transmission electron microscopy (TEM)/EDX analyses revealed that vertically aligned ZnO NRs (core dia. â¼181 ± 12 nm) arrays are conformally coated by an ultrathin ZnS (â¼25 ± 7 nm) shell layer with a preferential ZnS{111}/ZnO{10-10}-like partial epitaxy. The ZnO NRs exhibited a sharp band edge near â¼384 nm having optical bandgap energy (Eg) of â¼3.23 eV. However, the ZnO NR-ZnS CS exhibited double absorption bands atEgâ¼ 3.20 eV (ZnO-core) andEgâ¼ 3.78 eV (ZnS-shell). The ZnS{111}/ZnO{10-10}-nano-scaffolds could be utilized to facilitate the enhanced absorption of UV photons as well as the radial junction formation between the Pb-free perovskite absorber and ZnS/ZnO NRs layers.