Interfacial ZnS passivation for improvement of transparent ZnO/CuI diode characteristics

Transparent p–n Junction in Cu2O/ZnS/ZnO Core–Shell Nanoarrays via In Situ Sulfuration for Enhanced Photovoltaic Stability

“…The peaks at 1021.35 and 1044.37 eV are from Zn 2+ ions, and those at 529.73 and 531.77 eV are from Zn–O bond and–OH from absorbed water (Figure S1a,b), respectively, which confirm the formation of ZnO nanoarrays. − Further, the peaks at 161.18 and 162.32 eV are from S 2+ ions (Figure S1c), and the peak at 168.13 eV is from the surface-exposed S atoms. , Combined with Figure S1a, these results indicate the successful in situ sulfuration process and formation of ZnS shell. − The peaks at 932.35 and 952.18 eV are ascribed to Cu + from Cu 2 O film (Figure S1d). − In addition, the peaks at 934.57 and 954.88 eV are ascribed to Cu 2+, which resulted from surface oxidation during the test process. , Thus, the Cu 2 O/ZnS/ZnO core–shell orderly nanoarrays p–n junction with in situ dual functional ZnS transition layer was successfully formed.…”

“…The thickness of the ZnS shell is ∼25–30 nm. The lattice spacing of 0.259 (Figure b) and 0.311 (Figure c) nm can be ascribed to the (002) plane of ZnO − and (111) plane of ZnS, − respectively.…”

“…In addition to the FTO substrate, the observed diffraction peaks (Figure ) at 32.00°, 34.73°, 36.54°, 47.83°, 56.81°, 63.14°, and 68.17° are ascribed to the (100), (002), (101), (102), (110), (103), and (112) planes of ZnO (PDF# 36-1451), respectively. − With an increase in the duration of in situ sulfuration, an enhanced peak is observed at 28.84°, which is attributed to the (111) plane of ZnS (PDF# 05-0566). − However, restricted by the thinner thickness, the diffraction peaks intensity of ZnS is considerably lower than that of ZnO. The crystallinity of ZnO nanoarrays enhances with increased sulfuration time, indicating that the environment of in situ sulfuration can efficiently optimize the crystalline structure, including promoting the preferred growth .…”

“…42,43 Kim et al introduced ZnS for improving the transparent photoelectric property of ZnO/CuI. 44 Compared with other transition layer modifications, in situ sulfuration exhibits unique advantages. 45 During this process, the least lattice distortion occurs for ameliorating the heterojunction interface.…”

“…However, the current progress of transparent photovoltaic device has not been successful to meet the actual standards and requirements, because balancing carrier concentration and mobility has always been a bottleneck for transparent photoelectricity. − Hence, several efficient methods are being reported as a consequence of continuous research, , including surface modification and interface quantum dot modification or doping. Among these reported methods, transition layer modification with potential regulation and carrier injection has attracted considerable attention. , In particular, in addition to exhibiting adjustable potential, modification of the ZnS layer can alleviate the Fermi level gradient for improving carrier transportation and demonstrate higher quantum yield (QY) and wider bandgap, which can provide an effective carrier injection while sustaining good transparency. , Kim et al introduced ZnS for improving the transparent photoelectric property of ZnO/CuI . Compared with other transition layer modifications, in situ sulfuration exhibits unique advantages .…”