Tin selenide (SnSe) has attracted much attention in the field of thermoelectrics since the discovery of the record figure of merit (ZT) of 2.6 ± 0.3 along the b‐axis of the material. The record ZT is attributed to an ultralow thermal conductivity that arises from anharmonicity in bonding. While it is known that nanostructuring offers the prospect of enhanced thermoelectric performance, there have been minimal studies in the literature to date of the thermoelectric performance of thin films of SnSe. In this work, preferentially orientated porous networks of thin film SnSe nanosheets are fabricated using a simple thermal evaporation method, which exhibits an unprecedentedly low thermal conductivity of 0.08 W m⁻¹ K⁻¹ between 375 and 450 K. In addition, the first known example of a working SnSe thermoelectric generator is presented and characterized.

Solid-state lithium metal batteries show substantial promise for overcoming theoretical limitations of Li-ion batteries to enable gravimetric and volumetric energy densities upwards of 500 Wh kg⁻¹ and 1,000 Wh l⁻¹, respectively. While zero-lithium-excess configurations are particularly attractive, inhomogeneous lithium plating on charge results in active lithium loss and a subsequent coulombic efficiency penalty. Excess lithium is therefore currently needed; however, this negatively impacts energy density and thus limiting its thickness is essential. Here we discuss the viability of various technologies for realizing thin lithium films that can be scaled up to the volumes required for gigafactory production. We identify thermal evaporation as a potentially cost-effective route to address these challenges and provide a techno-economic assessment of the projected costs associated with the fabrication of thin, dense lithium metal foils using this process. Finally, we estimate solid-state pack costs made using thermally evaporated lithium foils.

Since the discovery of the record figure of merit (ZT) of 2.6 ± 0.3 in tin selenide (SnSe), the material has attracted much attention in the field of thermoelectrics. This paper reports a novel pseudo‐3D printing technique to fabricate bulk SnSe thermoelectric elements, allowing for the fabrication of standard configuration thermoelectric generators. In contrast to fabrication examples presented to date, this technique is potentially very low‐cost and allows for facile, scalable, and rapid fabrication. Bulk SnSe thermoelectric elements are produced and characterized over a wide range of temperatures. An element printed from an ink with 4% organic binder produces the highest performance, with a ZT value of 1.7 (±0.25) at 758 K. This is the highest ZT reported of any printed thermoelectric material, and the first bulk printed material to operate at this temperature. Finally, a proof‐of‐concept, all printed SnSe thermoelectric generator is presented, producing 20 µW at 772 K.

The looming impact of climate change and the diminishing supply of fossil fuels both highlight the need for a transition to more sustainable energy sources. While solar and wind can produce much of the energy needed, to meet all our energy demands there is a need for a diverse sustainable energy generation mix. Thermoelectrics can play a vital role in this, by harvesting otherwise wasted heat energy and converting it into useful electrical energy. While efficient thermoelectric materials have been known since the 1950s, thermoelectrics have not been utilized beyond a few niche applications. This can in part be attributed to the high cost of manufacturing and the geometrical restraints of current commercial manufacturing techniques. Printing offers a potential route to manufacture thermoelectric materials at a lower price point and allows for the fabrication of generators that are custom built to meet the waste heat source requirements. This review details the significant progress that has been made in recent years in printing of thermoelectric materials in all thermoelectric material groups and printing methods, and highlights very recent publications that show printing can now offer comparable performance to commercially manufactured thermoelectric materials.

DNA-mediated self-assembly of nanoparticles has been of great interest because it enables access to nanoparticle superstructures that cannot be synthesized otherwise. However, the programmability of higher order nanoparticle structures can be easily lost under DNA denaturing conditions. Here, we demonstrate that light can be employed as an external stimulus to master the stability of nanoparticle superlattices (SLs) via the promotion of a reversible photoligation of DNA in SLs. The oligonucleotides attached to the nanoparticles are encoded to ligate using 365 nm light, effectively locking the SLs and rendering them stable under DNA denaturing conditions. The reversible process of unlocking these structures is possible by irradiation with light at 315 nm, recovering the structures to their natural state. Our work inspires an alternative research direction toward postassembly manipulation of nanoparticle superstructures using external stimuli as a tool to enrich the library of additional material forms and their application in different media and environments.