Recent Progress in Colloidal Quantum Dot Thermoelectrics

Abstract

Semiconducting colloidal quantum dots (CQDs) represent an emerging class of thermoelectric materials for use in a wide range of future applications. CQDs combine solution processability at low temperatures with the potential for upscalable manufacturing via printing techniques. Moreover, due to their low dimensionality, CQDs exhibit quantum confinement and a high density of grain boundaries, which can be independently exploited to tune the Seebeck coefficient and thermal conductivity, respectively. This unique combination of attractive attributes makes CQDs very promising for application in emerging thermoelectric generator (TEG) technologies operating near room temperature. Herein, recent progress in CQDs for application in emerging thin‐film thermoelectrics is reviewed. First, the fundamental concepts of thermoelectricity in nanostructured materials are outlined, followed by an overview of the popular synthetic methods used to produce CQDs with controllable sizes and shapes. Recent strides in CQD‐based thermoelectrics are then discussed with emphasis on their application in thin‐film TEGs. Finally, the current challenges and future perspectives for further enhancing the performance of CQD‐based thermoelectric materials for future applications are discussed.

Recent progress in photovoltaic and thermoelectric applications of coupled colloidal quantum dot solids: insights into charge transport fundamentals

“…This can be attributed to the lesser number of interfaces and thus lesser interface related scattering hindrances. HgTe CQD based films have shown an increase in the Seebeck co-efficient with the decrease in QD sizes.For example,a 9.3 nm sized dot has a S of 1220 μV K −1 and a 3.7 nm dot has been found to have an increased S of 1890 μV K −1 .The maximum ZT attained by these p-type films is 0.092 whereas for n-type HgSe dot based films, the maximum achievable ZT at RT has been found to be 0.68 [128]. For majority of these HgX dots, the thermal conductivity varies as 0.17-0.29 Wm −1 K −1 [127,128].…”

The Latest Advances in Ink-Based Nanogenerators: From Materials to Applications

“…Semiconductor colloidal quantum dots (CQDs) have been recognized for their exceptional performance in the TE and optoelectronic domains, with their room-temperature TE performance nearing that of bulk Bi 2 Te 3 -based systems. These CQDs can be synthesized in bulk via straightforward wet chemical methods [ 61 ]. Numerous reviews have provided comprehensive summaries of the advancements in these four principal categories of TE materials from various perspectives.…”

“…While CQDs represent a relatively nascent class of semiconductor TE materials, the advancements in this area have been encapsulated in review articles. Mohamad Insan Nugraha et al [ 61 ] have provided a comprehensive overview of the predominant liquid-phase synthesis techniques for semiconductor CQDs, including hot injection, non-hot injection, laser irradiation, aqueous phase synthesis, and microwave-assisted synthesis. They further expounded on the current developments in hybrid CQDs/organic TE semiconductors, accentuating their promising applications in thin-film TEGs.…”