Inkjet printed P3HT:PCBM solar cells: A new solvent system approach
Inkjet printing and spin coating were used to deposit polymer passive layers and polymer:small molecular active layers consisting of poly(3-hexyl thiophene) and phenyl-C61 butyric acid methyl ester for organic solar cells. An inkjet solvent system consisting of chlorobenzene and trichlorobenzene was used where the ink's surface tension and viscosity were 32.5 mN/m and 1.0 to 1.5 mPa*s, respectively. Devices with inkjet printed passive and active layers were found to have slightly higher efficiency values with respect to solar cells with spin coated layers after pre-annealing. Additionally, it was determined that the achievable open circuit voltage of solar cells with inkjet printed or spin coated passive and active layers was within the range of 0.20 to 0.55 V.