胶体CdSe量子点敏化TiO_(2)太阳能电池中光电转换行为研究

Photo-to-electric Conversation Behavior in Colloidal CdSe Quantum Dots Sensitized TiO_(2) Solar Cell

以NaSeH_(4)水溶液、Cd^(2+)水溶液及巯基乙酸为原料采用水热法制备了水溶性CdSe量子点(QDs),并直接敏化在TiO_(2)光阳极上用于量子点敏化太阳能电池(QDSSC)。通过NaSeH_(4)的用量实现了CdSe QDs的尺寸调节和光谱响应范围调控。光伏性能分析表明尺寸约6nm的CdSe QDSSC效率达到2.26%,明显高于尺寸约4nm和10nm的CdSe QDSSC效率(分别为0.62%和1.39%)。光谱和阻抗分析表明合适的CdSe QDs尺寸能扩大光捕获效率并减少光阳极-电解液界面间的电荷复合,从而提高了光电转换效率。

CdSe colloidal quantum dots(QDs)have been synthesized by using NaSeH_(4),Cd^(2+)aqueous solution and thioglycollic acid,and directly deposited onto TiO_(2) photoanode for application in quantum dots sensitized solar cell(QDSC).The size and spectral response rage of CdSe QDs can be tuned by amount of NaSeH_(4).Photovoltaic performance tests show that a power conversion efficiency(PCE)of 2.26%can be achieved with~6 nm CdSe QDSC,which is higher than~4 nm CdSe QDSC and~10 nm CdSe QDSC(PCE are 0.62%and 1.39%,respectively).The spec-trum and impedance analysis show that the appropriate CdSe QDs size can expand the light trapping efficiency and reduce the charge recombination at the interface between photoanode and electrolyte,thus improving the photoelectric conversion efficiency.