Photoelectric Property Of Dye/Inorganic Semiconductor Sensitized TiO₂ Nanotube Arrays

Highly ordered TiO2 nanotube arrays (TNTs) semiconductor material prepared by electrochemistry anodization has the large surface area, and strong adsorption capacity. This thesis adopted the TiO2 nanotube arrays with anatase crystal structure as the light anode of photochemical solar cell. TiO2 has a bandgap of 3.2 eV and can only be activated by ultraviolet radiation. Photo-to-electric performance of pristine TiO2 is poor. Therefore, in order to improve anode photoelectric property, we use inorganics and dye sensitizer to modify TiO2 nanotube arrays.In2S3 belongs to ?-? compound semiconductor.In2S3 nanoparticles semiconductor material with ?-phase can be stabile at room temperature and n-type with a small bandgap of-2.0 eV. In2S3 nanoparticles were deposited on the TiO2 nanotube arrays by successive ionic layer absorption and reaction (SILAR) method. The optical response of the In2S3/TiO2 nanotube heterostructure arrays was extended. The conduction band (CB) of nanoparticles semiconductor material is higher than TiO2 nanotube arrays semiconductor material. More electrons were excited from VB of the In2S3 to CB, then transfer to the CB of TiO2 nanotube arrays semiconductor material and inhibited their recombination simultaneously, leading to better photoelectric conversion performance. In this work, we deposited In2S3 nanoparticles on TiO2 nanotube arrays via different concentrations precursor solutions. J-V characteristics showed that best PEC property was obtained in 0.1M InCl3, with the high conversion efficiency of 1.08%. With N719 as the co-sensitizing agent, the N719/In2S3/TiO2 nanotube heterostructure arrays solar cells were prepared. J-V characteristics showed that best PEC property of N719/In2S3/TiO2-based solar cells was the highest value of short-circuit current of 19.18 mA/cm2 and the highest value of conversion efficiency of 8.29% under AM 100 mW/cm2 illuminations.MoS2 is rich on the earth, and is inorganic fullerene displaying p-type conductivity. It has a small bandgap of 1.2-1.9 eV as the sensitizing agent of TiO2, depending on the thickness of the layer of MoS2. In this work, we deposited MoS2 nanoparticles on TiO2 nanotube arrays via hydrothermal method. J-V characteristics showed that best PEC property was the high conversion efficiency of 1.47%. With N719 as the sensitizing agent, the N719/MOS2/TiO2 dye-sensitized solar cells anode electrodes were prepared. J-V characteristics showed that best PEC property was the highest value of short-circuit current of 8.76 mA/cm-2 and the highest value of conversion efficiency of 2.45% under AM 100 mW/cm2 illuminations.The solar cell was modified by two processes, with different inorganics and then dye sensitizing agent, in order to improve anode photoelectric property. Different inorganics have different CB. For In2S3/TiO2, the CB of In2S3 nanoparticles semiconductor material is higher than TiO2 nanotube arrays semiconductor material. More electrons were excited from VB of the In2S3 to CB, then transfer to the CB of TiO2 nanotube arrays semiconductor material and inhibited their recombination simultaneously, leading to better photoelectric conversion performance. For MoS2/TiO2, the CB of MoS2 nanoparticles semiconductor material is lower than TiO2 nanotube arrays semiconductor material. It resulted in worse photoelectric conversion performance.