Effect of solvent on detectivity of solution-processed polymer photodetectors

We demonstrate a high-performance solution-processed polymer photodetector (PPD) whose detectivity (D*) exceeds 10(11) Jones over almost the entire range of visible light. PPDs processed from a chlorobenzene solution using 1,8-diiodooctane (DIO) as an additive exhibit large crystalline domains with long-range order, in contrast to the featureless morphology of PPDs processed with pure solvent. Moreover, PPDs processed with DIO exhibit higher charge carrier mobility, and thus high photoconductive gain without compromising long carrier lifetime. Consequently, a high-loading ratio of DIO (3%) yielded a PPD whose D* in the visible range was over threefold higher than that of PPD without DIO. (C) 2013 Optical Society of America