Molecules are predicted to be chemically tunable towards high thermoelectric efficiencies and they could outperform existing materials in the field of energy conversion. However, their capabilities at the more technologically relevant temperature of 300 K are yet to be demonstrated. A possible reason could be the lack of a comprehensive technique able to measure the thermal and (thermo)electrical properties, including the role of phonon conduction. Here, by combining the break junction technique with a suspended heat-flux sensor, we measured the total thermal and electrical conductance of a single molecule, at room temperature, together with its Seebeck coefficient. We used this method to extract the figure of merit zT of a tailor-made oligo(phenyleneethynylene)-9,10-anthracenyl molecule with dihydrobenzo[b]thiophene anchoring groups (DHBT-OPE3-An), bridged between gold electrodes. The result is in excellent agreement with predictions from density functional theory and molecular dynamics. This work represents the first measurement, within the same setup, of experimental zT of a single molecule at room temperature and opens new opportunities for the screening of several possible molecules in the light of future thermoelectric applications. The protocol is verified using SAc-OPE3, for which individual measurements for its transport properties exist in the literature.

预计分子可以通过化学方式调节以获得高热电效率，并且它们在能量转换领域的性能可能优于现有材料。然而，它们在技术上更相关的 300 K 温度下的能力尚未得到证实。一个可能的原因可能是缺乏能够测量热和（热）电特性（包括声子传导的作用）的综合技术。在这里，通过将断裂结技术与悬浮热通量传感器相结合，我们测量了室温下单个分子的总热导和电导及其塞贝克系数。我们使用这种方法提取了桥接​​在金电极之间的具有二氢苯并[ b ]噻吩锚定基团（DHBT-OPE3-An）的定制低聚（亚苯基乙炔基）-9,10-蒽基分子的品质因数zT 。结果与密度泛函理论和分子动力学的预测非常一致。这项工作代表了在相同装置内首次测量室温下单个分子的实验zT ，并为根据未来热电应用筛选几种可能的分子开辟了新的机会。该协议使用 SAc-OPE3 进行验证，文献中存在对其传输特性的单独测量。