Encapsulation of TiO2 nanotubes with Cs nanoparticles to enhance electron injection and thermal stability of perovskite solar cells

Abstract

The evolution of the Perovskite solar cells (PSC) has been remarkable with several milestones achieved in recent years. Intensive research is still ongoing to achieve the highly efficient PSCs with enhanced stability. The main problems of perovskite solar cells are relatively low power conversion efficiency (PCE) and less stability. This research work reports the improvement in performance of PSC by utilizing the encapsulation of TiO2 nanotubes with Cs nanoparticles to increase the electron injection rate and thermal stability. In this context, TiO2 Nanotubes and Cs-TiO2 Nanotubes have been synthesized by simple electrochemical anodization technique. SEM, EDX and XRD characterizations were engaged to observe the surface morphology, elemental composition and crystalline structure, respectively. UV/Vis spectra show that Cs-TiO2 nanotubes have higher optical absorption in the visible region than pure TiO2 nanotubes-based samples. The stability of PSC was evaluated by thermal gravimetric analyses (TGA), which showed only 2.5 % weight loss up to 800°C. Furthermore, J-V measurements were also performed, and it was observed that the Cs-TiO2 nanotubes-based PSCs presented an enhanced PCE of 13.24 %, which is higher than those of the PSCs based on pure TiO2 nanotubes. So, an enhanced PCE could be achieved by higher electron injection rate.