Boosting Photo-thermo-electric Conversion via a Donor–Acceptor Organic Cocrystal Strategy

Abstract

The inaugural instance of photo-thermo-electric conversion has been demonstrated based on the donor–acceptor organic cocrystal strategy due to its unique advantages. Notably, the selected cocrystal exhibits excellent broad solar absorption (200–2500 nm) and high near-infrared photothermal conversion efficiency. Combining organic cocrystals and thermoelectric devices upon 1 sun results in an exceptional open circuit voltage (0.427 V) and output power density (2.21 W·m–2), which is significantly better than traditional photothermal conversion materials. The fusion of organic cocrystals and high-output power density thermoelectric devices can offer a promising solar-based photo-thermo-electric conversion technology for outdoor portable power generation and remote rural areas.

Primary Structural Units “D+A–” Ion Pairs Dominating Near-Infrared Photothermal Conversion of Organic Ionic Cocrystals

“…More significantly, regardless of the stacking modes, the minimum η value of these F4TCNQ-based cocrystals is superior to 70%. Compared to other types of photothermal materials including carbon-based materials, inorganic semiconductors, plasmonic materials or polymers, the unique advantages of organic cocrystals are supported by the direct comparison on the solar-driven photothermal water evaporation rate/efficiency under 1 Sun by Chun-Sing Lee et al Besides, our recent results also reveal the superiority of organic cocrystals for photothermo-electric applications compared to other types of photothermal materials . This excellent performance supports that beneath the secondary segregated/mixed stacking modes of D/A blocks, there are primary structural units, e.g., “D + A – ” ion pairs from strong charge transfer interactions, that dominate the NIR-PTC performance of ionic cocrystals.…”

“…Subsequently, several groups quickly followed up to improve the NIR-PTC properties of cocrystals in terms of enhancing NIR absorption and facilitating the nonradiative transition process. − The endeavors based on strong charge-transfer, π–π stacking, p-π interaction, hydrogen bonds, halogen bonds, etc. between D/A units , make the cocrystal systems potential candidates for photothermal imaging/therapy, , photothermal-electric devices, and seawater desalination applications. , …”

Rationally Integrating Charge-Transfer Cocrystal and Ni(II) Organometallics for Visualized Photo/Thermochromic Sensors

“…Photothermal materials with unique solar energy harvesting for thermal energy concentration demonstrate great potential of thermal stimuli for inducing the thermochromic process of [(C 2 H 5 ) 2 NH 2 ] 2 NiCl 4– x Br x organometallics. , On account of the inherent superiorities within organic cocrystals and the fascinating photothermal conversion ability, organic photothermal cocrystals have attracted ample interests in both fundamental research and practical applications, such as photoacoustic imaging, photothermal therapy, seawater desalination, and so on . Directed by these advantages, TCBQ with intense electron affinity and TMBD were respectively employed as the electron acceptor and donor to construct TMBD-TCBQ organic cocrystals based on CT interaction as depicted in Figure a.…”

Lattice Architectures for Thermoelectric Energy Harvesting

“…The vast amount of untapped heat released into the environment allows thermoelectrics to be a candidate for a low-cost sustainable clean energy solution, with low-grade heat accounting for >50% of total heat dissipated from industries , (Figure c) . In addition, sunlight can also be converted into electricity through photothermal materials applied on TEGs, which is suitable for outdoor portable power generation.…”