reSeArCH Letter
Extended Data Fig. 10 | Thermal durability of doped PBTTT thin films.
These UV–vis–NIR spectra were obtained from doped PBTTT thin films
before and after annealing at the indicated temperatures. a, An F4TCNQ-
doped PBTTT thin film. b–i, Anion-exchange-doped films with:
b, K 2 CO 3 ; c, BMIM-FAP; d, BMIM-FeCl 4 ; e, BMIM-BF 4 ; f, BMIM-PF 6 ;
g, BMIM-TFSI; h, Li-PFSI; and i, Li-BOB. j, Ratios of conductivity before
and after annealing at 120 °C and 160 °C. Details of doping conditions are
provided in the Supplementary Information.