Sambur Justin B, Parkinson Bruce A
Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States.
ACS Appl Mater Interfaces. 2014 Dec 24;6(24):21916-20. doi: 10.1021/am507974h. Epub 2014 Dec 8.
Cadmium selenide quantum dots covalently attached to and photosensitizing single-crystal TiO2 surfaces are observed to corrode under illumination in aqueous electrolyte containing iodide as a regenerator. Comparison of photocurrent spectra before and after long-term monochromatic illumination indicated that the CdSe QD sensitizers photocorroded and decreased in size until their band gap energy exceeded the excitation energy. This wavelength-dependent photoelectrochemical etching mechanism can be used to tune the size distribution of surface adsorbed QDs and may account for the instability of QD sensitized solar cells that do not employ sulfide-based electrolytes.
观察到共价连接并光敏化单晶TiO₂表面的硒化镉量子点在含有碘化物作为再生剂的水性电解质中光照下会发生腐蚀。长期单色光照前后光电流光谱的比较表明，CdSe量子点敏化剂发生光腐蚀且尺寸减小，直至其带隙能量超过激发能量。这种波长依赖性的光电化学蚀刻机制可用于调节表面吸附量子点的尺寸分布，并可能解释了不采用硫化物基电解质的量子点敏化太阳能电池的不稳定性。
