本研究主要是進行太陽能電池之光陽極結構的探討。在結構上，主要是以不同比例的二氧化鈦奈米柱與奈米粒子混合構成。在奈米柱的製備上則是以水熱法進行，並經過700oC退火處理2小時後，得到銳鈦礦相之二氧化鈦奈米柱。前期以不同的二氧化鈦奈米柱與奈米粒子混合比例製備成太陽能光陽極進行N719染料分子的吸附，找出較佳的光陽極製備條件。根據研究的結果指出以全部為奈米粒子組成之光陽極，經由硝酸做表面處理修飾後，再於結構層上添加大小不同尺寸的二氧化鈦奈米粒子做為散射層，其光電轉換效率與效率值分別為40%與6.24%。另外，將藉由調制光電流/光電壓分析系統，可進行電子的傳遞特性分析，以得到結構層之最佳厚度。
而在CdSe量子點敏化型光陽極的研究方面，先以3-巰基丙酸進行二氧化鈦光陽極表面改質，使3-巰基丙酸之羧基接上二氧化鈦光陽極表面，再利用另一端的硫醇官能基鍵結於CdSe量子點表面，做為晶種層。之後，再經由反應性離子吸附與反應法來增加量子點的被覆量。由研究的結果顯示：當使用的光陽極厚度較厚時，則CdSe量子點將無法有效地被覆於光陽極結構上。此一結果可藉由掃描式穿隧電子顯微鏡之高角度環狀暗視野成像法獲得證實。而在本研究中，以3.5 m厚度之光陽極進行四次的反應性離子吸附與反應程序，可得太陽能電池效率達0.86%。

In this research, the main research topic focuses on the study of photoanode with various anatase phase titanium dioxide (TiO2) nanoparticles/nanorods hybrid structure. The hydrothermal method was employed to grow 1-D titanate nanorods, and the as-grown product was annealed at 700oC for 2 hours to transfer 1-D titanate to anatase TiO2 nanorods. In the first part, N-719 dyes were sensitized on the photoanode with various hybrid structures of TiO2 nanorods and P25 particles and find out the optimal photoanode fabrication condition. From the experimental results, the photoanode fabricated with nitric acid treated P25-TiO2 nanoparticles and added various large size TiO2 nanoparticles as scattering layer can obtain IPCE of 40% and efficiency of 6.24%. In addition, the electron transport properties can be characterized by intensity-modulated photocurrent spectroscopy (IMPS) and intensity-modulated photovoltage spectroscopy (IMVS). From this analysis, the optimal photoanode thickness can be determined.
In the second part, N-719 dye molecules were replaced by cadmium selenide quantum dots (CdSe-QDs) to sensitized photoanode as solar cells. Before linking CdSe-QDs, 3-mercaptoproponic acid was used to modify the surface of TiO2 photoanode. In the bifunctional molecules, the carboxyl group was anchored on the surface of TiO2 photoanode and thiol group was linked on the surface of CdSe-QDs. In order to increase QDs absorbed amount, successive ion layer absorption and reaction (SILAR) method was employed to decorate the photoanode by multiple cycles. From scanning transmission electron microscopy-high angle annual dark field (STEM-HAADF) analysis, we can observe the CdSe-QDs accumulate on the top of photoanode. In this study, the higher efficiency of 0.86% of CdSe-QDs sensitized solar cells can be obtained by SILAR process with 4 cycles.

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