Data related to manuscript ['Bipolarons rule the short-range terahertz conductivity in electrochemically doped P3HT', Materials Horizons (2022), https://pubs.rsc.org/en/content/articlelanding/2022/mh/d1mh01343b]

Doping of organic semiconductor films enhances their conductivity for applications in organic electronics, thermoelectrics and bioe- lectronics. However, much remains to be learnt about the proper- ties of the conductive charges in order to optimize the design of the materials. Electrochemical doping is not only the fundamental mechanism in organic electrochemical transistors (OECTs), used in biomedical sensors, but it also represents an ideal playground for fundamental studies. Benefits of investigating doping mechanisms via electrochemistry include controllable doping levels, reversibility and high achievable carrier densities. We introduced here a new technique, applying in situ terahertz (THz) spectroscopy directly to an electrochemically doped polymer in combination with spectro- electrochemistry and chronoamperometry. We evaluate the intrin- sic short-range transport properties of the polymer (without the effects of long-range disorder, grain boundaries and contacts), while precisely tuning the doping level via the applied oxidation voltage. Analysis of the complex THz conductivity reveals both the mobility and density of the charges. We find that polarons and bipolarons need to co-exist in an optimal ratio to reach high THz conductivity (B300 S cm

有机半导体薄膜的掺杂可提升其电导率，适用于有机电子学、热电学与生物电子学等领域。然而，要优化材料设计，人们对其载流子性质仍有诸多待深入探究之处。电化学掺杂不仅是应用于生物医学传感器的有机电化学晶体管（organic electrochemical transistors，OECTs）的核心工作机制，同时也是开展基础研究的理想平台。通过电化学方法探究掺杂机制的优势包括掺杂水平可控、过程可逆且可实现较高的载流子密度。本文提出一种全新技术：将原位太赫兹（terahertz，THz）光谱技术与光谱电化学、计时电流法相结合，直接应用于电化学掺杂的聚合物体系。我们通过精准调控施加的氧化电压来调节掺杂水平，同时评估聚合物的本征短程输运性质（排除长程无序、晶界及电极接触的影响）。对复太赫兹电导率的分析可同时获取载流子的迁移率与密度。研究发现，极化子与双极化子需以最优比例共存，才能实现较高的太赫兹电导率（约300 S cm）。