磷摻雜之二氧化鈦奈米管應用於分解水及染料敏化太陽能電池

Abstract

本實驗主要想了解磷摻雜二氧化鈦奈米管在分解水與染料敏化太陽能電池中的效應。作者利用了SEM、XPS、XRD、EPMA等儀器去定性磷摻雜在二氧化鈦的物理特性，了解到磷離子(P5+)可以部分取代鈦(Ti4+)，產生charge imbalance降低電子-電洞再結合能力。在分解水實驗中有摻雜磷效率比未摻雜的效率高，原因是 UV-Vis吸收光譜可以看到有紅位移現象，表示可以增加長波長光的吸收，有助於效率的提升。染料敏化太陽能電池作者測試了TiCl4的處理條件，可以有效提升光電轉換效率。但是隨著電解液磷酸濃度的增加，造成奈米管長度變短，管子出現龜裂現象，使光電轉換效率降低。最後也沉積III-V半導體氮化銦，從UV-Vis吸收光譜看到可以增加光波長吸收範圍與強度，使光電轉換效率增加約11%。

In this study we investigate the effect of phosphorous doping in TiO2 on water-splitting and DSSC efficiencies. We take advantage of SEM, XPS, XRD and EPMA analyses to characterize the P-doped TiO2 nanotubes. We found that phosphorous ion (P5+) could partially replace of titanium ion (Ti4+), resulting in charge imbalance which can decrease the electron-hole recombination. In the experiment of water-splitting, we can clearly see that the efficiency of P-doped TiO2 nanotubes is higher than the undoped ones, because the P-doped sample has shown a red-shift in the UV-Vis absorption spectrum. The absorption in the long-wavelength results in the increase in the efficiency of water-splitting. We also tested the effects of treatment on the doped TiO2 nanotubes with TiCl4 and varying the concentration of H3PO4 in the anodization electrolyte, the former treatment led to enhanced DSSC efficiencies, whereas the latter test showed that a higher H3PO4 concentration gave rise to shortened nanotubes with observable cracks and lower DSSC efficiencies. We also deposited InN semiconductor on P-doped TiO2 nanotubes by plasma enhanced chemical vapor deposition; we could see clearly the enhanced absorption wavelength range and absorption intensity, resulting in an enhancement in photoconversion by 11%.