Figure 1

(a) Electron mobility in silicon at $T$ $=$ 300 K (Ref. 40). $N_0$ for Si is set as its atomic density (5 × 10${}^{22}$ cm${}^{-3}$). (b) OSC mobility at 300 K as calculated by Eq. (9) (solid and dashed lines) and a master equation for hopping transport (Ref. 6) (symbols). α $=$ 0.1$l$ is used for both and $b$ is set to unity. Also shown is the low carrier concentration expression of Eq. (11) (dot-dashed lines). (c) Calculation of $\left|S\right|$.Reuse & Permissions

Figure 2

(a) and (b) Calculated $S$ and σ for various α. Measured room temperature data for pentacene FETs (Ref.10) (closed symbols), doped bulk pentacene films (Ref. 27) (open symbols), and silicon (Ref. 41) are also shown. $N_0$ $=$ 2.9×10${}^{21}$ cm${}^{-3}$ is used for pentacene (Ref. 24). Measured FET channel densities are converted to carrier concentrations based on the effective FET channel thickness (3 nm) (Ref. 28). Measured dopant mole fractions for the bulk film are converted to carrier concentrations based on $b$ $=$ 0.76 as reported for F${}_4$-TCNQ in pentacene (Ref. 27). Measured field-effect mobility is used to calculate σ for the FET, since it is typically similar to the Hall mobility for small molecular FETs (Refs. 10 and 29). (c) Temperature dependence of mobility for several values of α at $n/N_0$ $=$ 10${}^{-2}$, a typical concentration for operating FETs.Reuse & Permissions

Figure 3

(a) Room temperature S${}^2$σ measured (Ref. 15) in PEDOT:Tos (symbols) and calculated for a general OSC and silicon (lines) (Refs. 40 and 41). The value of $v_0$ derived for PEDOT:Tos (1×10${}^{14}$ s${}^{-1}$) for ox > 16$\%$ is assumed in general OSC calculations. (b) $S$ and σ vs $n/N_t$ for PEDOT:Tos (Ref. 15) (open symbols) and PEDOT:Pss (Ref. 36) (closed symbols). $N_t$ $=$ 10${}^{21}$ cm${}^{-3}$ and r ∼ 1 (based on molecular weights of Tos and EDOT) are used for numerical calculations (Ref. 39). (c) Effective ionization fraction calculated for PEDOT:Tos (symbols) and a fit to Eq. (13) (dashed line).Reuse & Permissions

Figure 4

Fits of the model to further experimental data, demonstrating how $d\left|S\right|/dT$ changes as α increases from an activated ($\left|S\right|$ ∼ 1/$T$) regime in NTCDA to an intermediate ($\left|S\right|$ ∼ const.) regime in pentacene to a VRH ($\left|S\right|$ ∼ $T$) regime in polyacetylene.Reuse & Permissions