CdSe/ZnS Quantum Dot (QD) Sensitized Solar Cell Utilizing a Multi-Walled Carbon Nanotube Photoanode on a Stainless Steel Substrate

摘要

Multi-walled carbon nanotube (MWCNT) forests grown on a stainless steel substrate were used as a photoanode in CdSe/ZnS (core/shell) quantum dot (QD) sensitized solar cells (QDSSCs). QD-treated MWCNTs on the conductive metal stainless steel substrate showed a higher power conversion efficiency (PCE) of 0.015% than those grown on a doped silicon substrate with a PCE of 0.005% under AM 1.5 sunlight intensity (100 mW/cm2). This higher efficiency can be attributed to the lower sheet resistance of 0.0045 Ω/sq for the metal substrate than that for doped silicon of 259 Ω/sq. The relationship between the total reflectance of the as-prepared CNT photoanode and the PCE was investigated for CNTs of various heights and amounts of QDs. A QDSSC fabricated using a CNT photo anode with a height of 25 μm showed the highest efficiency of 0.014%, while a pristine CNT forest showed the lowest total reflectance of 1.9%, which indicates a higher surface area of CNTs and a larger amount of QDs. The as-grown 25-μm CNTs treated with QDs containing in a toluene solution of 25-μL of exhibited the highest PCE of 0.015%, due to the larger surface area of the CNTs and the higher light absorption from the large amount of QDs on the CNTs.