Thin Film of TiO₂–ZnO Binary Mixed Nanoparticles as Electron Transport Layers in Low-Temperature Processed Perovskite Solar Cells

Abstract

Organic–inorganic hybrid perovskite solar cells have become one of the highly promising candidates for photovoltaic technologies because of their low processing cost, rapid-growing power conversion efficiency and easy preparation process. Electron transfer layer (ETL) plays an important role in exciton separation and charge transport for perovskite devices. A TiO2–ZnO binary mixed nanoparticle (NP) ETL, which can be prepared in low-temperature hydrothermal method, was proposed. By analyzing the XRD and SEM, the incorporation of mixed NPs thin film improved the interfacial stability of ZnO/perovskite and prevented the perovskite layer from being decomposed as compared to the pure ZnO NPs thin film. Furthermore, UV spectrum and EIS results show that TiO2–ZnO mixed NP ETL has high transmittance and maintains good electrical properties of pure ZnO NPs basically. Finally, the efficiency of perovskite device based on TiO2–ZnO mixed NP ETL was improved to 15%. Our research provides a simple way for the application of ZnO in PCSs.

Recent Progress in Perovskite Solar Cells: Status and Future

“…The performance of related PSCs is shown in Table 1. Bilayer ETLs also work well, such as TiO 2 /SnO 2 [57][58][59][60][61][62][63][64][65][66], TiO 2 /ZnO [67,68], TiO 2 /WO 3 [69,70], TiO 2 /graphene [71,72], TiO 2 /fullerene [73], and TiO 2 /NiO [74].…”

Influence of Zn(NO3)2 concentration during the ZnO electrodeposition on TiO2 nanosponges used in photoelectrochemical applications

“…In addition, for TiO2/ZnO hybrid nanosponges electrodeposited with a Zn(NO3)2 concentration of 30 mM, the charge transfer resistance decreases both in dark and illuminated conditions compared to TiO2 nanosponges. This decrease may happen due to the fact that TiO2/ZnO hybrid nanostructures have a greater number of defects as a consequence of the introduction of ZnO into the nanostructures, obtaining a more efficient charge separation and a greater number of charge carriers [30,33,50,52,53].…”

Perspectives on the mechanical robustness of flexible perovskite solar cells

“…However, the intralayer thermal stress resulting from the large difference in thermal expansion between the flexible substrates and the functional layers may induce defects in the functional layers, resulting in stress concentrations during service and leading to more rapid degradation. To date, many studies on low-temperature fabrication methods have been explored 8,9 including low-temperature hydrothermal processes, 10 ultraviolet ozone treatment, 11 and N 2 plasma treatment strategies. 12 Li et al 13 recently reported that FPSCs subjected to methylamine gas treatment exhibit outstanding flexibility and retain 94.5% of the initial PCE after 3000 bending cycles.…”