A method of forming an organic layer for an organic electronic device, comprising: having a liquid composition comprising a small molecule organic semiconductor material mixed in a solvent preparation, the solvent preparation comprising a solvent and 0.1 wt% or less of impurities having a higher boiling point than the solvent, the solvent having a boiling point higher than 250 °C at 1 atm; and depositing the liquid composition on a surface; wherein the solvent preparation is a purified solvent preparation, and wherein providing the liquid composition comprises: having a crude solvent preparation comprising the solvent and more than 0.1 wt% of impurities having a higher boiling point than the solvent and a main impurity having a boiling point lower than the solvent, wherein the impurities having a higher boiling point than the solvent constitute 10% or less of total impurities; purifying the crude solvent preparation by removing at least some of the impurities having a higher boiling point than the solvent to obtain the purified solvent preparation, wherein a magnitude of a ratio of the impurities having a higher boiling point than the solvent to the main impurity in the purified solvent preparation as measured by gas chromatography-mass spectrometry is less than a magnitude of the ratio in the crude solvent preparation; and mixing the small molecule organic semiconductor material with the purified solvent preparation. having a liquid composition comprising a small molecule organic semiconductor material mixed in a solvent preparation, the solvent preparation comprising a solvent and 0.1 wt% or less of impurities having a higher boiling point than the solvent, the solvent having a boiling point higher than 250 °C at 1 atm; and depositing the liquid composition on a surface; wherein the solvent preparation is a purified solvent preparation, and wherein providing the liquid composition comprises: having a crude solvent preparation comprising the solvent and more than 0.1 wt% of impurities having a higher boiling point than the solvent and a main impurity having a boiling point lower than the solvent, wherein the impurities having a higher boiling point than the solvent constitute 10% or less of total impurities; purifying the crude solvent preparation by removing at least some of the impurities having a higher boiling point than the solvent to obtain the purified solvent preparation, wherein a magnitude of a ratio of the impurities having a higher boiling point than the solvent to the main impurity in the purified solvent preparation as measured by gas chromatography-mass spectrometry is less than a magnitude of the ratio in the crude solvent preparation; and mixing the small molecule organic semiconductor material with the purified solvent preparation. having a crude solvent preparation comprising the solvent and more than 0.1 wt% of impurities having a higher boiling point than the solvent and a main impurity having a boiling point lower than the solvent, wherein the impurities having a higher boiling point than the solvent constitute 10% or less of total impurities; purifying the crude solvent preparation by removing at least some of the impurities having a higher boiling point than the solvent to obtain the purified solvent preparation, wherein a magnitude of a ratio of the impurities having a higher boiling point than the solvent to the main impurity in the purified solvent preparation as measured by gas chromatography-mass spectrometry is less than a magnitude of the ratio in the crude solvent preparation; and mixing the small molecule organic semiconductor material with the purified solvent preparation.