Organic Based Flexible Speaker Through Enhanced Conductivity of PEDOT/PSS with Various Solvents

Flexible organic film speaker (FOFS) was fabricated with ion assisted reaction (IAR) treated poly (vinylidene fluoide) (PVDF) as active layer and poly (3,4-ethylenedioxythiophene)/poly (4-styrenesulfonate) (PEDOT/PSS), indium tin oxide (ITO) and Cu as electrodes DC conductivity (σ DC ) of pristine PEDOT/PSS increases from 0.8 to 80 S/cm with adding various organic solvents [dimethyl sulfoxide (DMSO), N, N-dimethyl formamide (DMF), tetrahydrofuran (THF)]. The increase of σ DC of PEDOT/PSS results from screening effect of organic solvents. Frequency response of sound pressure level (SPL) of film speaker is discussed in term of total current by applied electric field. The SPL of PVDF film speaker with highly conducting PEDOT/PSS (DMSO) electrode shows more flat SPL in the frequency range from 400 Hz to 10 kHz compare to Cu or ITO electrode.