Fabrication Of FTO With Tunable Pores For Application In Perovskite Solar Cells And Hydrogen Peroxide Sensors

Due to the high transparency,electrical conductivity and stability,FTO(SnO2:F)has been widely used in energy conversion devices,energy storage devices,optical devices,catalytic devices,sensors and so on.The performance of FTO in its applications can be greatly improved by introducing pores to increase the surface area while keeping the high electrical conductivity and transparency.The previously reported porous FTO(PFTO)is usually prepared using electrochemical etching or other costly or more complicated methods.Here a simple and low-cost method has been developed firstly for preparing PFTO.The PFTOs with tunable pore sizes and densities can be prepared by immersing the FTO spin-coated with the commercial zinc powder dispersed in ethanol in a mixed solution of aqueous hydrochloric acid and ethanol.By simply modifying the zinc powder concentration,spin coating speed,and the ethanol volume ratio,the pore diameter and density can be adjusted in the ranges of 22-120 nm,and 9-120/μm2,respectively.The mixture of Zn powder and acid has been usually used to etch FTO,but the corresponding mechanism has been scare.In this thesis,the valence variations of tin,the main composition of FTO,were studied before and after the etching reaction by XPS,furthermore,the valence variations of tin were confirmed by mimicking the corrosive solutions monitored using absorption spectra,and the corrosion mechanism of FTO by the mixture of Zn and hydrochloric acid has been proposed.The porous structure of PFTO can greatly enhance the performance of the device.In this thesis,PFTOs were used to prepare the new inverted solar cell structure without hole transport layer.Compared with FTO,the energy conversion efficiency was increased by 1.5 times.The PFTO was also used as the host substrate of NiO to detect hydrogen peroxide sensor.Compared with FTO,the detective sensitivity of hydrogen peroxide was enhanced by 3.7 times.