ИСТИНА

We present a technique for in situ probing of the molecular order in organic photovol taic cells by Raman spectroscopy. Raman spectra of the polymer (P3HT) in the polymer -fullerene blends are measured during film anneali ng and fitted as a superposition of two components that correspon d to the amorphous and quasi crystalline P3HT phase s. We show that the annealing dynamics of the quasi crystallin e polymer phase provides the correleation between t he annealing temperature and the device efficiency . The develop ed method allows optimization of the treatment proc ess of organic solar cells based on the future heterogeneous formu lations to increase their efficiency.