16:00 〜 16:15
▲ [20p-W323-9] Thermoelectric Properties of Colloidal Quantum Dot Solids
キーワード：nanostructure thermoelectric materials,colloidal quantum dots,nanocrystals
Colloidal quantum dot solids (QDS) are solution-processable thin-films that exploit the quantum confinement properties of the constituent nanocrystals. The quantum confinement effect occurred in this materials generates distinct features than their bulk counterparts that are energy bandgap variations by size and the quasi-atom-like discrete energy levels. the discrete energy levels with sharp peaks of their density of states, are prospective for developing new thermoelectric material systems. Moreover, the QD diameters are smaller than phonon mean-free-path, thus predicted to have low thermal conductivity. Nevertheless, the low electronic conductivity of the QDS still hamper this possible applications. Here we demonstrate the field-induced doping control in monolayers of PbS QDS by the use of ionic liquid gating. it allow us to access the preserved discrete energy levels of the QDs. Through this capability, we establish a way to characterize the thermoelectric properties of monolayers of QDS, from which a high value of Seebeck coefficient more than 1 mV/K is demonstrated.