Optimization of Thermoelectric Performance in p-Type SnSe Crystals Through Localized Lattice Distortions and Band Convergence.

Crystalline thermoelectric materials, especially SnSe crystals, have emerged as promising candidates for power generation and electronic cooling. In this study, significant enhancement in ZT is achieved through the combined effects of lattice distortions and band convergence in multiple electronic valence bands. Density functional theory (DFT) calculations demonstrate that cation vacancies together with Pb substitutional doping promote the band convergence and increase the density of states (DOS) near the Fermi surface of SnSe, leading to a notable increase in the Seebeck coefficient (S).

Energy Band Alignment and Defect Synergistic Regulation Enable Air-Solution-Processed Kesterite Solar Cells With the Lowest V Deficit.

The major challenge in preparing high-performance CuZnSn(S,Se) solar cells is the large open circuit voltage deficit (V-def). A new strategy utilizing the synergistic substitution of Ag and In dual cations has been proposed to simultaneously address the problems of undesirable interface band alignment and high-density detrimental bulk defects, obtaining decreased carrier recombination rate and increased minority carrier lifetime. The shorter In-S/Se bonds move the CBM higher by generating stronger repulsive force than the Sn-S/Se bonds, thus adjusting the interface band alignment.

Optimization of Thermoelectric Performance of AgTe Films via a Co-Sputtering Method.

Providing self-powered energy for wearable electronic devices is currently an important research direction in the field of thermoelectric (TE) thin films. In this study, a simple dual-source magnetron sputtering method was used to prepare AgTe thin films, which exhibit good TE properties at room temperature, and the growth temperature and subsequent annealing process were optimized to obtain high-quality films. The experimental results show that films grown at a substrate temperature of 280 °C exhibit a high power factor (PF) of ~3.

Rapid Thermal-Driven Crystal Growth and Defect Suppression in Antimony Selenide Thin Film for Efficient Solar Cells.

Antimony selenide (SbSe) has demonstrated considerable potential and advancement as a light-absorbing material for thin-film solar cells owing to its exceptional optoelectronic characteristics. However, challenges persist in the crystal growth, particularly regarding the nucleation mechanism during pre-selenization process for SbSe. The defects originating from this process significantly impact the quality of the absorber layer, leading to the degradation in the power conversion efficiency (PCE) of the device.

Achieving High Thermoelectric Performance in Bi(Te, Se) Thin Film with (00)-Oriented by Incorporating Tellurization and Selenization Processes.

Flexible thermoelectric (TE) generators have received great attention as a sustainable and reliable option to convert heat from the human body and other ambient sources into electricity. This study provides a synthesis route that involves thermally induced diffusion to introduce Te and Se into Bi, fabricating an n-type Bi-Te-Se flexible thin film on a flexible substrate. This specific synthesis alters the crystal orientation (00) of the thin film, improving in-plane electrical transportation and optimizing carrier concentration.

Deviceization of high-performance and flexible AgSe films for electronic skin and servo rotation angle control.

AgSe shows significant potential for near-room-temperature thermoelectric applications, but its performance and device design are still evolving. In this work, we design a novel flexible AgSe thin-film-based thermoelectric device with optimized electrode materials and structure, achieving a high output power density of over 65 W m and a normalized power density up to 3.68 μW cm K at a temperature difference of 42 K.

Optimization of Thermoelectric Properties and Physical Mechanisms of CuSe-Based Thin Films via Heat Treatment.

CuSe is an attractive thermoelectric material due to its layered structure, low cost, environmental compatibility, and non-toxicity. These traits make it a promising replacement for conventional thermoelectric materials in large-scale applications. This study focuses on preparing CuSe flexible thin films through in situ magnetron sputtering technology while carefully optimizing key preparation parameters, and explores the physical mechanism of thermoelectric property enhancement, especially the power factor.

Anion/Cation Co-Doping to Improve the Thermoelectric Performance of Sn-Enriched n-Type SnSe Polycrystals with Suppressed Lattice Thermal Conductivity.

Enhancing the thermoelectric performance of n-type polycrystalline SnSe is essential, addressing challenges posed by elevated thermal conductivity and compromised power factor inherent in its intrinsic p-type characteristics. This investigation utilized solid-state reactions and spark plasma sintering techniques for the synthesis of n-type SnSe. A significant improvement in the figure of merit (ZT) is achieved through strategic reduction in Se concentration and optimization of crystal orientation.

Ultraflexible Temperature-Strain Dual-Sensor Based on Chalcogenide Glass-Polymer Film for Human-Machine Interaction.

Skin-like thermoelectric (TE) films with temperature- and strain-sensing functions are highly desirable for human-machine interaction systems and wearable devices. However, current TE films still face challenges in achieving high flexibility and excellent sensing performance simultaneously. Herein, for the first time, a facile roll-to-roll strategy is proposed to fabricate an ultraflexible chalcogenide glass-polytetrafluoroethylene composite film with superior temperature- and strain-sensing performance.

Flexible power generators by AgSe thin films with record-high thermoelectric performance.

Exploring new near-room-temperature thermoelectric materials is significant for replacing current high-cost BiTe. This study highlights the potential of AgSe for wearable thermoelectric electronics, addressing the trade-off between performance and flexibility. A record-high ZT of 1.

High Seebeck Coefficient Inorganic GeGaTe Core/Polymer Cladding Fibers for Respiration and Body Temperature Monitoring.

Wearable thermal sensors based on thermoelectric (TE) materials with high sensitivity and temperature resolution are extensively used in medical diagnosis, human-machine interfaces, and advanced artificial intelligence. However, their development is greatly limited by the lack of materials with both a high Seebeck coefficient and superior anticrystallization ability. Here, a new inorganic amorphous TE material, GeGaTe, with a high Seebeck coefficient of 1109 μV/K is reported.

Suppressing Buried Interface Nonradiative Recombination Losses Toward High-Efficiency Antimony Triselenide Solar Cells.

Antimony triselenide (Sb Se ) has possessed excellent optoelectronic properties and has gained interest as a light-harvesting material for photovoltaic technology over the past several years. However, the severe interfacial and bulk recombination obviously contribute to significant carrier transport loss thus leading to the deterioration of power conversion efficiency (PCE). In this work, buried interface and heterojunction engineering are synergistically employed to regulate the film growth kinetic and optimize the band alignment.

High-Performance Thermoelectric Flexible AgSe-Based Films with Wave-Shaped Buckling via a Thermal Diffusion Method.

Herein, an n-type AgSe thermoelectric flexible thin film has been fabricated on a polyimide (PI) substrate via a novel thermal diffusion method, and the thermoelectric performance is well-optimized by adjusting the pressure and temperature of thermal diffusion. All of the AgSe films are beneficial to grow (013) preferred orientations, which is conducive to performing a high Seebeck coefficient. By increasing the thermal diffusion temperature, the electrical conductivity can be rationally regulated while maintaining the independence of the Seebeck coefficient, which is mainly attributed to the increased electric mobility.

Cadmium-Free Kesterite Thin-Film Solar Cells with High Efficiency Approaching 12.

Cadmium sulfide (CdS) buffer layer is commonly used in Kesterite Cu ZnSn(S,Se) (CZTSSe) thin film solar cells. However, the toxicity of Cadmium (Cd) and perilous waste, which is generated during the deposition process (chemical bath deposition), and the narrow bandgap (≈2.4 eV) of CdS restrict its large-scale future application.

Charge Transport Enhancement in BiVO Photoanode for Efficient Solar Water Oxidation.

Photoelectrochemical (PEC) water splitting in a pH-neutral electrolyte has attracted more and more attention in the field of sustainable energy. Bismuth vanadate (BiVO) is a highly promising photoanode material for PEC water splitting. Additionally, cobaltous phosphate (CoPi) is a material that can be synthesized from Earth's rich materials and operates stably in pH-neutral conditions.

Energy Band Alignment by Solution-Processed Aluminum Doping Strategy toward Record Efficiency in Pulsed Laser-Deposited Kesterite Thin-Film Solar Cell.

Kesterite-based CuZnSnS (CZTS) thin-film photovoltaics involve a serious interfacial dilemma, leading to severe recombination of carriers and insufficient band alignment at the CZTS/CdS heterojunction. Herein, an interface modification scheme by aluminum doping is introduced for CZTS/CdS via a spin coating method combined with heat treatment. The thermal annealing of the kesterite/CdS junction drives the migration of doped Al from CdS to the absorber, achieving an effective ion substitution and interface passivation.

Enhanced Thermoelectric Performance of CoSb Thin Films by Ag and Ti Co-Doping.

The Skutterudites CoSb material has been the focus of research for the conversion applications of waste heat to electricity due to its ability to accommodate a large variety of ions in the cages that have been proven effective in improving the thermoelectric performance. Although the co-doped CoSb bulk materials have attracted increasing attention and have been widely studied, co-doped CoSb thin films have been rarely reported. In this work, Ag and Ti were co-doped into CoSb thin films via a facile in situ growth method, and the influence of doping content in the thermoelectric properties was investigated.

Effects of Si Substrates with Variable Initial Orientations on the Growth and Thermoelectric Properties of Bi-Sb-Te Thin Films.

For thermoelectric thin film, the substrate plays an important role during the growing process and produces effects on its thermoelectric properties. Some special kinds of substrates provide an optimal combination of influences on both the structure and thermoelectric properties. In this work, Bi-Sb-Te films are deposited on Si substrates with different initial orientations by magnetron sputtering in two ways: with and without a pre-coating process.

Optimized Thermoelectric Properties of Sulfide Compound BiSeS by Iodine Doping.

The Te-free compound Bi2SeS2 is considered as a potential thermoelectric material with less environmentally hazardous composition. Herein, the effect of iodine (I) substitution on its thermoelectric transport properties was studied. The electrical conductivity was enhanced due to the increased carrier concentration caused by the carrier provided defect Ise.

Crystal Growth Promotion and Defect Passivation by Hydrothermal and Selenized Deposition for Substrate-Structured Antimony Selenosulfide Solar Cells.

Antimony sulfide-selenide (Sb(S,Se)) is a promising light-harvesting material for stable and high-efficiency thin-film photovoltaics (PV) because of its excellent light-harvesting capability, abundant elemental storage, and excellent stability. This study aimed to expand the application of Sb(S,Se) solar cells with a substrate structure as a flexible or tandem device. The use of a hydrothermal method accompanied by a postselenization process for the deposition of Sb(S,Se) film based on the solar cell substrate structure was first demonstrated.

Heterojunction Annealing Enabling Record Open-Circuit Voltage in Antimony Triselenide Solar Cells.

Despite the fact that antimony triselenide (Sb Se ) thin-film solar cells have undergone rapid development in recent years, the large open-circuit voltage (V ) deficit still remains as the biggest bottleneck, as even the world-record device suffers from a large V deficit of 0.59 V. Here, an effective interface engineering approach is reported where the Sb Se /CdS heterojunction (HTJ) is subjected to a post-annealing treatment using a rapid thermal process.

Crystal Growth Promotion and Defects Healing Enable Minimum Open-Circuit Voltage Deficit in Antimony Selenide Solar Cells.

Antimony selenide (Sb Se ) is an ideal photovoltaic candidate profiting from its advantageous material characteristics and superior optoelectronic properties, and has gained considerable development in recent years. However, the further device efficiency breakthrough is largely plagued by severe open-circuit voltage (V ) deficit under the existence of multiple defect states and detrimental recombination loss. In this work, an effective absorber layer growth engineering involved with vapor transport deposition and post-selenization is developed to grow Sb Se thin films.

Organic Chloride Salt Interfacial Modified Crystallization for Efficient Antimony Selenosulfide Solar Cells.

Antimony selenosulfide, Sb(SSe), is recognized as an excellent photoactive material owing to its light harvesting capability. There is still room for improvement of the film quality for device performance improvement. Herein, an organic chloride salt [diethylamine hydrochloride, DEA(Cl)] has been introduced for fabricating Sb(SSe) solar cells for the first time.

Novel Thermal Diffusion Temperature Engineering Leading to High Thermoelectric Performance in Bi Te -Based Flexible Thin-Films.

Flexible Bi Te -based thermoelectric devices can function as power generators for powering wearable electronics or chip-sensors for internet-of-things. However, the unsatisfied performance of n-type Bi Te flexible thin films significantly limits their wide application. In this study, a novel thermal diffusion method is employed to fabricate n-type Te-embedded Bi Te flexible thin films on flexible polyimide substrates, where Te embeddings can be achieved by tuning the thermal diffusion temperature and correspondingly result in an energy filtering effect at the Bi Te /Te interfaces.

Homo-composition and hetero-structure nanocomposite Pnma BiSeS - Pnnm BiSeS with high thermoelectric performance.

Nanocomposite engineering decouples the transport of phonons and electrons. This usually involves the in-situ formation or ex-situ addition of nanoparticles to a material matrix with hetero-composition and hetero-structure (heC-heS) interfaces or hetero-composition and homo-structure (heC-hoS) interfaces. Herein, a quasi homo-composition and hetero-structure (hoC-heS) nanocomposite consisting of Pnma BiSeS - Pnnm BiSeS is obtained through a Br dopant-induced phase transition, providing a coherent interface between the Pnma matrix and Pnnm second phase due to the slight structural difference between the two phases.