The simulation result shows that light is mainly guided inside th

The simulation result shows that light is mainly guided inside the shells of the top layer nanofilm, and strong light absorption based on the WGM resonances is observed. Furthermore, we measure the UV-visible

(UV-vis) absorption spectra of the ZnO/ZnS, ZnS/ZnO, and ZnO nanofilms in Figure 4a. One can see that the absorbance is more prominent in the ZnO/ZnS bilayer nanofilm, but it is about one third of the simulated absorption spectrum of the ZnO/ZnS bilayer nanofilm (see Figure 4b). This could mainly be caused by the scattering due to the imperfect arrays (or defects) in our samples (see Figure 1c), which weaken the light absorption based Dabrafenib on the WGM resonances to some extent. The big challenge is how to use this interfacial self-assembly strategy to grow high-quality multilayer nanofilms with uniform coverage ratios and smooth surfaces suitable for use in these optoelectronic devices. Even so, we could make a conclusion that the use of wavelength-scale resonant hollow spheres in our bilayer nanofilms supports whispering gallery modes to enhance light absorption and then photocurrent. Figure 2 Electric field (| E |) distribution and absorption power distribution. (a) Electric field (|E|) distribution based on full-wave simulation of electromagnetic waves coupled with the ZnO hollow-sphere nanofilm at 370 nm. (b)

DNA Damage inhibitor Power distribution of the ZnO hollow-sphere nanofilm at 370 nm. (c) Electric field (|E|) distribution based on full-wave simulation of electromagnetic waves coupled with the ZnO hollow-sphere nanofilm at 350 nm. (d) Power distribution of the ZnO hollow-sphere nanofilm at 350 nm. Figure 3 Electric field (| E |) distribution. (a) Electric field (|E|) distribution based on full-wave simulation of electromagnetic waves coupled with the ZnO/ZnS hollow-sphere

nanofilm at 370 nm. (b) Electric field (|E|) distribution based on full-wave simulation of electromagnetic waves coupled with the ZnS/ZnO hollow-sphere nanofilm at 370 nm. Figure Guanylate cyclase 2C 4 UV-vis absorption spectra. (a) UV-vis absorption spectra of the ZnO, ZnO/ZnS, and ZnS/ZnO nanofilms. (b) Absorption spectra simulated from the ZnO, ZnO/ZnS, and ZnS/ZnO nanofilm structures. It is very important to effectively separate the photogenerated carriers within the optoelectronic devices. The ZnO/ZnS and ZnS/ZnO bilayer nanofilms made of ZnO and ZnS hollow nanospheres can be regarded as heterostructured assemblies. The position of the valence band (VB) energy level of ZnS is about 0.6 eV higher than that of ZnO, and a type II heterostructure with a staggered alignment at the heterojunction is formed in our bilayer nanofilms [20]. The presence of an internal electric field due to the band bending at the heterostructure interface facilitates the separation of photogenerated carriers (see Figure 5). By the effective absorption of photons with energy greater than the bandgap, electron-hole pairs are photogenerated in semiconductor nanostructures.

Comments are closed.