胶体 CdSe/CdTe 核壳Ⅱ型量子点敏化太阳能电池

摘要

In order to investigate the application prospect of the type Ⅱ quantum dot (QD)sensi-tized solar cell,CdSe /CdTe QD is used as the sensitizer of TiO2 in the photoanode,instead of the traditional sensitizer dye,which is fabricated through the colloid chemical method.The structure of the quantum dot-sensitized solar cell (QDSSC)includes three parts,the photoanode,platinum counter electrode and electrolyte.The power conversion efficiency (PCE)of the QDSSC is 0.86%according to the measurement results of photovoltaic conversion.By analyzing the result of the fluo-rescence decay of type Ⅱ QD adsorbed on the TiO2 and FTO substrate and the electrochemical im-pedance spectroscopy (EIS),the mechanism of the solar cell is discussed.The comparison between two fluorescence decay lifetimes indicates that the carrier transport rate from CdSe /CdTe QD to TiO2 is relatively slow and then the charge recombination rate is enhanced,so the current density of the CdSe /CdTe core /shell QDSSC becomes lower.The results of the EIS illustrate that the electron life-time of the CdSe /CdTe QDs is longer,which indicates that the type Ⅱ QD has potential applications in the field of solar cells.%为了探讨Ⅱ型量子点在敏化太阳能电池中的应用前景，采用胶体化学法制备了 CdSe /CdTe 核壳Ⅱ型量子点，替代染料敏化 TiO2形成光阳极，与 Pt 对电极、电解液组装成量子点敏化太阳能电池．电池光电转换性能测量结果表明该电池具有0．86％的能量转换效率．通过测量Ⅱ型量子点吸附在 TiO2和 FTO 基板上的荧光寿命、电池的电化学阻抗谱，探讨电池性能的内在机理．荧光寿命测量结果表明电子从 CdSe /CdTe 转移到 TiO2上速率较慢，从而电荷复合的几率提高，导致 CdSe /CdTe 核壳量子点敏化电池的短路电流密度较低．电化学阻抗谱表明Ⅱ型量子点具有更长的电子寿命，由此显示其在太阳能电池应用上具有潜在的优势．