Analysis of charge transport in high-mobility diketopyrrolopyrole polymers by space charge limited current and time of flight methods

Abstract

The hole mobility of the widely studied diketopyrrolopyrole-based polymers (PDPPDTSE) was examined using space charge limited current (SCLC) and time of flight (TOF) methods. The mobility of the hole-only device based on PDPPDTSE was found to be dependent upon the e-field over the range of 10⁻³ to 10⁻² cm² V⁻¹ s⁻¹ with nearly identical Poole–Frenkel coefficients. In addition, we found that the mobility strongly depended on the thickness of the PDPPDTSE. By analyzing the temperature dependence of transport characteristics, we argued that the charge transport in this polymer was greatly influenced by trap distribution at the electrode/semiconductor interface.