Self-Organized One-Dimensional TiO_𝟐 Nanotube/Nanowire Array Films for Use in Excitonic Solar Cells: A Review

Table 2

Device names and their key fabrication details [12].

Device name	Volume of SOM—0.17 M/ Li salt—19.5 mM/ TBP—0.12 M in CB (μL)	Volume of DCM-pyran in CB Concentration—24 mM (μL)	Volume of DCM-pyran in CB Concentration—48 mM (μL)	Volume of CB (μL)	Wetting time before spin coating Sec.
Conc. SOM	30	—	—		60
Dilute SOM	30	—	—	15	90
DCM 10	30	10	—		75
DCM 30	30	30	—		90
DCM 40	30	40	—		120
DCM 50	30	50	—		120
DCM 30–48 mM	30	—	30		90

Note: SOM stands for Spiro-OMeTAD. Li salt for Bis(trifluoromethylsulfonyl)amine lithium salt, 99.95% trace metals basis. TBP for 4-tert-Butylpyridine. CB for Chlorobenzene. DCM-pyran for 4-(Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran. Solutions were spin coated on SQ-1 acceptor dye-sensitized TiO₂ nanotubes at 2000 rpm. The 0.02 M TiCl₄-treated TiO₂ nanotubes are from 500 to 600 nm in length, and 20 to 28 nm pore size.