XPS and UPS characterization of the TiO2/ZnPcGly heterointerface:: Aligmment of energy levels
XPS and UPS characterization of the TiO2/ZnPcGly heterointerface:: Aligmment of energy levels
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DOI：
10.1021/jp014192b
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发表时间：
2002-06-13
影响因子：
3.3
通讯作者：
Sun, LC
中科院分区：
文献类型：
--
作者：
Liu, GM;Jaegermann, W;Sun, LC
通过X射线光电子能谱（XPS）和紫外光电子能谱（UPS）对纳米结构的TiO₂/ZnPcGly染料敏化剂的分子半导体异质界面的电子结构以及最高占据分子轨道（HOMO）/最低未占据分子轨道（LUMO）的排列进行了表征。确定染料ZnPcGly的HOMO能级位于费米能级边缘以下1.62 eV处，并且根据通过光吸收测量确定的ZnPcGly的HOMO/LUMO能隙（1.82 eV），估计相应的LUMO能级位于TiO₂导带上方0.10 eV处。染料轨道与TiO₂能带之间的这种能级匹配能够使光激发的ZnPcGly向TiO₂进行有效的电子转移，这在光诱导电荷转移反应以及染料敏化太阳能电池的应用中非常重要。
The electronic structure and the highest occupied molecular orbitals (HOMO)/the lowest unoccupied molecular orbitals (LUMO) alignment at the molecular semiconductor heterointerface of nanostructured TiO2/ZnPcGly dye sensitizer were characterized by X-ray and ultraviolet photoemission spectroscopy (XPS and UPS). The HOMO level of the dye ZnPcGly was determined to be located at 1.62 eV below the Fermi edge, and the corresponding LUMO level was estimated to be 0.10 eV above the conduction band of TiO2 based on the HOMO/LUMO gap (1.82 eV) of ZnPcGly determined by optical absorption measurements. This energy level matching between the orbitals of the dye and the bands of TiO2 can enable efficient electron transfer from photoexcited ZnPcGly to TiO2, which is very important in photoinduced charge-transfer reactions and for applications in dye-sensitized solar cells.