ZnS/Al2S3 Layer as a Blocking Layer in Quantum Dot Sensitized Solar Cells

In this research, the effect of treatment of the CdS/CdSe sensitized ZnO photoanode by ZnS, Al2S3, and ZnS/Al2S3 nanoparticles as a barrier layer on the performance of quantum dot sensitized solar cell is investigated. Current density-voltage (J-V) characteristics show that cell efficiency is enhanced from 3.62% to 4.82% with treatment of a CdS/CdSe/ZnS sensitized ZnO photoanode by Al2S3 nanoparticles. In addition, short- circuit current density (J (sc)) is increased from 11.5 mA/cm(2) to 14.8 mA/cm(2). The results extracted from electrochemical impedance spectroscopy indicate that charge transfer resistance (R (ct)) in photoanode/electrolyte interfaces decreases with deposition of Al2S3 nanoparticles on CdS/CdSe/ZnS sensitized ZnO photoanodes, while the chemical capacitance of photoanode (C (mu) ) and electron lifetime (t (n)) increase. Also, results revealed that cell performance is considerably decreased with the treatment of the AL(2)S(3) blocking layer incorporated between ZnO nanorods and CdS/CdSe QDs.