Thermoelectric Figure Of Merit Research Articles

Magnetic and Electrical Properties of CuCr2Se4 Nanoparticles

CuCr2Se4 nanoparticles were obtained by the high-energy ball milling of CuCr2Se4 single crystals, which had a size of approximately 32 nm after 5 h of milling. Structural, magnetic, and electrical studies have shown that a reduction in CuCr2Se4 single crystals to the nanosize leads to (1) a weakening of ferromagnetic interactions, both long and short range, (2) a lack of saturation of magnetization at 5 K and 70 kOe, (3) a change in the nature of electrical conductivity from metallic to semiconductor, and (4) a reduction in the thermoelectric power factor S2σ by an order of magnitude of 400 K. The above results were considered in terms of the parameters of the band model, derived from the high-temperature expansion of magnetic susceptibility and from the diffusive component of thermoelectric power. Theoretical calculations showed a significant weakening of both the superexchange and double exchange mechanisms, a reduction in the [Cr3+,Cr4+] band width from 0.76 to 0.19 eV, and comparable values of the Fermi energy and the activation energy (0.46 eV) in the intrinsic region of electrical conductivity. The main advantage of high-energy ball milling is the ability to modify the physicochemical properties of already existing compounds for desired applications.

Incommensurately Modulated Cu0.9Pb1.2Sb2.9Se6 in the Lillianite Structure Type.

Samples with the nominal composition Cu0.9Pb1.2Sb2.9Se6 mainly contain a phase with incommensurately modulated lillianite-type structure with the respective composition. Single crystal diffraction with synchrotron radiation enabled a detailed refinement using the superspace group Cmcm(α00)00s with lattice parameters a = 4.16537(5), b = 14.0821(2), c = 19.8234(3) Å, and a modulation vector q = 0.6890(2)a* at room temperature. The structure is built up from tilted and distorted NaCl-type slabs that are interconnected by bicapped trigonal prisms, which mainly host Pb atoms, according to a 4L arrangement. Satellites up to the second order reveal positional and occupational modulation that mainly involves a sequence of Sb and Cu atoms and allows the Se substructure to adapt in a way that Sb and Cu feature predominantly octahedral and tetrahedral coordination, respectively. Above 523 K, satellite reflections disappear, and the crystal structure becomes more disordered with average coordination spheres of both Sb and Cu atoms corresponding to distorted octahedra. This phase transition leads to discontinuities in the evolution of lattice parameters and physical properties as functions of temperature. HRTEM investigations corroborate centrosymmetry and highlight atoms that are strongly affected by the modulation. Measurements of transport properties reveal a p-type semiconductor with a thermoelectric figure of merit up to 0.1 at 623 K. In accordance with B factor analysis, a small amount of substitution could increase zT significantly by optimizing the carrier concentration.

Enhanced thermoelectric properties of self-assembling ZnO nanowire networks encapsulated in nonconductive polymers

The near-room temperature thermoelectric properties of self-assembling ZnO nanowire networks before and after encapsulation in nonconductive polymers are studied. ZnO nanowire networks were synthesized via a two-step fabrication technique involving the deposition of metallic Zn networks by thermal evaporation, followed by thermal oxidation. Synthesized ZnO nanowire networks were encapsulated in polyvinyl alcohol (PVA) or commercially available epoxy adhesive. Comparison of electrical resistance and Seebeck coefficient of the ZnO nanowire networks before and after encapsulation showed a significant increase in the network's electrical conductivity accompanied by the increase of its Seebeck coefficient after the encapsulation. The thermoelectric power factor (PF) of the encapsulated ZnO nanowire networks exceeded the PF of bare ZnO networks by ~ 5 and ~ 185 times for PVA- and epoxy-encapsulated samples, respectively, reaching 0.85 μW m−1 K−2 and ZT ~ 3·10–6 at room temperature, which significantly exceeded the PF and ZT values for state-of-the-art non-conductive polymers based thermoelectric flexible films. Mechanisms underlying the improvement of the thermoelectrical properties of ZnO nanowire networks due to their encapsulation are discussed. In addition, encapsulated ZnO nanowire networks showed excellent stability during 100 repetitive bending cycles down to a 5 mm radius, which makes them perspective for the application in flexible thermoelectrics.

Enhanced thermoelectric performance with improved mechanical strength in Bi2S3/graphite composites

In spite of possessing high Seebeck coefficient and low thermal conductivity, Bi2S3 suffers from poor electrical conductivity, which makes it challenging to use for application in thermoelectric power generator (TEG). In the present work, we have used graphite (G) to improve the electron transport in Bi2S3 by making a composite. Here, we have obtained ZT∼0.15 at room temperature in n-type Bi2S3, which is much higher than that reported for sulphides at room temperature. The inclusion of graphite in Bi2S3, provides a conductive pathway for the easy transport of electrons, and leads to a surge in electrical conductivity. As a result, a high thermoelectric power factor ∼643 μW/m-K2 is attained, which is 30 times higher than that of pristine Bi2S3 at room temperature. The maximum ZT ∼0.3 is obtained for 1.5 wt% graphite-Bi2S3 composite at 705 K temperature. Furthermore, the mechanical strength of Bi2S3 is found to be significantly improved by graphite inclusion, which offers better load bearing capacity for practical application as TEG.

Towards Optimizing Width Modulation for Maximum Thermoelectric Efficiency.

Maximizing thermoelectric efficiency is typically addressed as identical to minimizing parasitic thermal conduction. Such an approach relies on the assumption that the adopted strategy mainly affects phonons, leaving electrons intact, and is not justified in many cases of non-uniform nanostructures such as width-modulated nanowaveguides, where both electrons and phonons are significantly affected by width modulation. Here, we address the question of maximizing the thermoelectric efficiency of this class of metamaterials by exploring the effect of the modulation extent on both electron and phonon transport. We investigated the effect of increasing modulation degree on the thermoelectric efficiency, considering the cases of (a) a two-QD modulation and (b) multiple-QD modulations in periodic and aperiodic sequences. We show that the thermoelectric efficiency depends on the coupling between the modulation units and the interplay between periodicity and aperiodicity in the modulation profile. We reveal that the maximization of the thermoelectric power factor is for periodic width-modulation, whereas the maximization of the thermoelectric efficiency is for aperiodic width-modulation profiles that form quasi-localized states for electrons. Our work provides new insight that can be used to optimize width modulation for maximum thermoelectric efficiency.

Electrochemical charge-carrier modulation of carbon nanotubes using ionic liquids derived from organic superbases for stable thermoelectric materials

Carbon nanotubes (CNTs) are attractive candidates for thermoelectric (TE) device components. However, a doping strategy for precise charge-carrier modulation and stabilization of the doped states of the CNTs is essential for thermoelectric applications. In particular, existing n-type CNTs tend to have inadequate stability in air and at elevated temperatures. In this study, we used newly synthesized ionic liquids (ILs) derived from organic superbases and bis(trifluoromethanesulfonyl)imide (TFSI) for electrochemical doping, expecting these ions to function as stabilizers of the n- and p-doped states of CNTs, respectively. The thermoelectric power factor was optimized by modulating the Seebeck coefficient and electrical conductivity over a wide range of values by varying the polarity and magnitude of the applied potential. Furthermore, n- and p-type doping could be simultaneously realized for the working and counter CNT electrodes by the one-time application of a potential. The doped states were retained as an electric double layer on the CNT electrodes even after their removal from the electrolyte solution. In particular, the use of ILs derived from bicyclic ring superbases and TFSI were shown to stabilize both n- and p-type CNTs at high temperatures for extended periods of time. Our approach is useful for preparing TE materials with an optimized power factor, controlled polarity, and long-term thermal stability.

Thermoelectric and transport properties of half-Heusler FeNb1-xTixSb alloys

In this work, Ti-doped FeNbSb half-Heusler alloys were synthesized by arc and induction melting techniques. The samples were then thermally treated for 48 h at 923 K in evacuated silica tubes. Powders of the prepared samples were alloyed via ball milling for 2 h in an argon atmosphere at milling speed of 450 rpm to obtain nanocomposites. Crystal structure, elemental distribution and morphological properties were examined throughout the diffraction patterns of X-ray, scanning by the electronic microscope alongside with energy dispersive x-ray spectroscopy. Transport and thermoelectric properties were investigated over a wide temperature range between 300 and 800 K. The electrical conductivity was significantly improved due to the Ti doping which then resulted in remarkable increase in the thermoelectric power factor. The electrical conductivity showed an increase from 46 Ω−1cm−1 to 3000 Ω−1cm−1 with an improvement of 98 %, at room temperature. At high temperature (800 K), The electrical conductivity increased from 150 Ω−1cm−1 to 1414 Ω−1cm−1, upon doping. A maximum power factor of 21 μW cm−1 K−2 for the highest Ti doped sample (FeNb0.8Ti0.2Sb), achieved at 800 K. Alongside improving the electrical conductivity, a remarkable reduction in the lattice and the total thermal conductivity was achieved due to Ti doping, over the whole temperature range. The lattice thermal conductivity exhibited a notable reduction from 12 W/m.K for the pristine FeNbSb alloy to 8.5 W/m.K for the Ti-doped FeNb0.8Ti0.2Sb alloy, at room temperature with a reduction of ∼30 %. The total thermal conductivity of the parent compound decreased from 12.05 W/m.K to 7.4 W/m.K, at room temperature. Accordingly, a promising figure of merit was recorded at around 0.20 for FeNb0.8Ti0.2Sb sample, at 800 K. A notable improvement in the figure of merit, zT with a percentage of ∼ (84–92) % at 800 K is obtained, in comparison to that of the parent FeNbSb alloy, due to Ti doping. ZT is increased from 0.0011, for the parent FeNbSb sample, to 0.05 for the highest-doped FeNb0.8Ti0.2Sb sample, at room temperature. Moreover, it increased from 0.015 for the parent sample to 0.2 for the highest-doped sample, at 800 K.

Aerosol doping of SWCNT films with p- and n-type dopants for optimizing thermoelectric performance

We investigate the aerosol doping method for a thermoelectric performance enhancement of single-walled carbon nanotube (SWCNT) films. A study of doping behavior by depositing an aerosolized dopant solution and real-time optimization of thin film properties focuses on thermoelectric characteristics. Achieving precise control over doping results, we demonstrated the thermoelectric power factor of 657 and 708 μW/mK2 for, respectively, p-type and n-type doped SWCNT films. The proposed doping strategy offers superior flexibility for device design and comparable performance to solution-based doping, paving the way to efficient and scalable thermoelectric generator production based on carbon nanotube materials.

Epoxy-Encapsulated ZnO-MWCNT Hybrid Nanocomposites with Enhanced Thermoelectric Performance for Low-Grade Heat-to-Power Conversion.

This work is devoted to the development of epoxy-encapsulated zinc oxide-multiwalled carbon nanotubes (ZnO-MWCNT) hybrid nanostructured composites and the investigation of their thermoelectric performance in relation to the content of MWCNTs in the composite. For the preparation of nanocomposites, self-assembling Zn nanostructured networks were coated with a layer of dispersed MWCNTs and subjected to thermal oxidation. The resulting ZnO-MWCNT hybrid nanostructured networks were encapsulated in commercially available epoxy adhesive. It was found that encapsulation of ZnO-MWCNT hybrid networks in epoxy adhesive resulted in a simultaneous decrease in their electrical resistance by a factor of 20-60 and an increase in the Seebeck coefficient by a factor of 3-15, depending on the MWCNT content. As a result, the thermoelectric power factor of the epoxy-encapsulated ZnO-MWCNTs hybrid networks exceeded that of non-encapsulated networks by more than 3-4 orders of magnitude. This effect was attributed to the ZnO-epoxy interface's unique properties and to the MWCNTs' contribution. The processes underlying such a significant improvement of the properties of ZnO-MWCNT hybrid nanostructured networks after encapsulation in epoxy adhesive are discussed. In addition, a two-leg thermoelectric generator composed of epoxy-encapsulated ZnO-MWCNT hybrid nanocomposite as n-type leg and polydimethylsiloxane-encapsulated CuO-MWCNT hybrid nanocomposite as p-type leg characterized at room temperatures showed better performance at temperature difference 30 °C compared with the similar devices, thus proving the potential of the developed nanocomposites for applications in domestic waste heat conversion devices.

Dopant induced band convergence leading to high thermoelectric power factor in Mg2Sn

Band convergence is a common technique for enhancing the power factor of thermoelectric (TE) materials. This is usually achieved by solid solution formation in compounds having specific electronic band features. In this work, we show that a similar band convergence effect can be achieved in Mg2Sn by doping with small amounts of Bi. To identify this effect and the possible reason behind it, a detailed investigation of the electronic band structure (EBS) has been carried out using a recently developed multi-band refinement technique (MBRT). Nominal compositions of Mg2.2Sn1-xBix (x = 0,0.005, 0.01, 0.0125, 0.015, 0.02) have been synthesized by induction melting followed by compaction using uniaxial hot-pressing. Measurement of Seebeck coefficient (S), electrical conductivity (σ) and Hall Coefficient (RH) have been performed between 300K–700K and the data used for multi-band refinement. Results indicate changes in the inter-band separation of conduction bands with doping content and temperature. Significantly lower inter-band separation compared to reported undoped data is found even for the lowest doped composition, resulting in both conduction bands contributing to the power factor (S2σ). Further, for the heavily doped compositions (x = 0.0125, 0.015, 0.02) band-flipping between the conduction bands has been observed. Thus, the light conduction band is found to constitute the conduction band edge in the heavily doped compositions. This is contrary to the reported EBS of undoped Mg2Sn in which the heavy conduction band has a lower energy. Also, increasing temperature results in band convergence in the heavily doped compositions. A plausible cause for the band-flipping behaviour is provided based on merging of the impurity band with the light conduction band in heavily doped Mg2Sn. The band-flipping and the subsequent band convergence results in an even higher S2σ in the heavily doped compositions. The work highlights the beneficial influence of Bi doping on the TE properties of Mg2Sn and opens the possibility of utilizing dopants for achieving band convergence in TE materials.

Y and La Doping in CaMnO3 Compounds: Effects of Dopant Identity and Amount on Charge Transport Kinetics

Enhancing electronic transport properties of thermoelectric oxides is of great technological importance. Oxides are promising candidates for waste heat harvesting at elevated temperatures as well as for electricity generation in low‐power applications. To this purpose, fundamental understanding of their electrical and thermal conduction mechanisms is essential. Herein, the conduction mechanism of CaMnO3 materials is focused on and how dopant identity and amount alter the kinetic properties of charge transport is investigated. Ca1−xRxMnO3 compounds with R = Y and La are synthesized, where 0 ≤ x ≤ 0.13, and the electrical conductivity and Seebeck coefficient for temperatures ranging from 300 to 1050 K, indicating that Y‐doped compounds are usually more conductive than their La‐doped counterparts, are measured. Analysis of both in terms of the small polaron hopping model reveals that Y doping reduces conduction activation energies, resulting in higher electrical conductivity and charge carrier mobility. Remarkably high values of thermoelectric power factor for the Ca0.97La0.03MnO3 compound, for example, 300 μWm−1 K−2 at 1050 K are observed; furthermore, these values are preserved for a wide temperature range, rendering this compound a good candidate for heat‐to‐electrical power generation at elevated temperatures.

Large-area nanofiber membrane of NIR photothermal Cs0.32WO3 for flexible and all-weather solar thermoelectric generation

Harvesting heat or solar energy to directly generate affordable and sustainable electricity holds great promise toward both fundamental science and practical applications in self-powered wearable electronics. However, solar thermoelectric (STE) devices remain challenging in establishing a stable and significant temperature gradient (ΔT) across thermoelectric materials for cost-effective electricity generation. Herein, a wearable STE generator with all-weather and high-performance electricity generation was elaborately designed and synthesized sandwiched by a thermogalvanic cell and a large-area nanofiber membrane of Cs0.32WO3 (CWO) nanoparticles with strong near-infrared (NIR) absorption. These prepared CWO membranes, which were prepared via an electrostatic spinning technique, present a high photothermal conversion efficiency of 42.7 % with no degradation after running for 10 cycles. Notably, a significant ΔT of 31.5 K across the thermoelectric modular was achieved for STE generation via the thermal concentration of these photothermal membranes under natural sunlight. Owing to the high thermopower of 2.87 mV K−1 for each p-n pair, STE generation demonstrates a maximum output voltage of 200 mV under natural solar irradiance during the time period of noon. This work explores a new strategy to achieve efficient heat management of STE devices for high electricity generation under all-weather conditions, which demonstrates great potential for self-powered wearable electronics.

Highly Conductive n‐Type Polymer Fibers from the Wet‐Spinning of n‐Doped PBDF and Their Application in Thermoelectric Textiles

AbstractThe field of electronic textiles currently lacks n‐type polymer fibers that can complement the more established p‐type polymer fibers. Here, a highly conductive n‐type polymer fiber is obtained via wet‐spinning of n‐doped poly(3,7‐dihydrobenzo[1,2‐b:4,5‐b’]difuran‐2,6‐dione) (n‐PBDF). The electrical conductivity of the fibers increases from 1000 to 1600 S cm−1 with increased draw during processing and correlates well with Young's modulus. Wide‐angle X‐ray scattering reveals the existence of a bimodal orientation of the polymer chains, favoring parallel alignment to the fiber axis with increased draw. After 14 d in 80% humid air, fiber conductivity stabilizes maintaining 81% of the initial conductivity. Although the electrical conductivity drops slightly over time, the Seebeck coefficient increases, resulting in the highest thermoelectric power factor being measured at 91 µW m−1 K−2 for the most drawn fiber 14 d after its fabrication. A proof‐of‐concept two‐couple thermoelectric textile is crafted by embroidering bundles of n‐type PBDF fibers and p‐type PEDOT:PSS fibers. The device generates 2.40 nW at a 22 °C temperature gradient. This work represents the initial steps and a crucial advancement toward fabricating high‐performance n‐type polymer fibers that can complement their p‐type counterparts to close the existing performance gap.

Electron-hole dichotomy and enhancement of the thermoelectric power factor by electron-hole-asymmetric relaxation time: A model study on a two-valley system with strong intervalley scattering

Electron-hole dichotomy and enhancement of the thermoelectric power factor by electron-hole-asymmetric relaxation time: A model study on a two-valley system with strong intervalley scattering

Largely Enhanced Thermoelectric Power Factor of Flexible Cu2-xS Film by Doping Mn.

Copper-sulfide-based materials have attracted noteworthy attention as thermoelectric materials due to rich elemental reserves, non-toxicity, low thermal conductivity, and adjustable electrical properties. However, research on the flexible thermoelectrics of copper sulfide has not yet been reported. In this work, we developed a facile method to prepare flexible Mn-doped Cu2-xS films on nylon membranes. First, nano to submicron powders with nominal compositions of Cu2-xMnyS (y = 0, 0.01, 0.03, 0.05, 0.07) were synthesized by a hydrothermal method. Then, the powders were vacuum-filtrated on nylon membranes and finally hot-pressed. Phase composition and microstructure analysis revealed that the films contained both Cu2S and Cu1.96S, and the size of the grains was ~20-300 nm. By Mn doping, there was an increase in carrier concentration and mobility, and ultimately, the electrical properties of Cu2-xS were improved. Eventually, the Cu2-xMn0.05S film showed a maximum power factor of 113.3 μW m-1 K-2 and good flexibility at room temperature. Moreover, an assembled four-leg flexible thermoelectric generator produced a maximum power of 249.48 nW (corresponding power density ~1.23 W m-2) at a temperature difference of 30.1 K, and had good potential for powering low-power-consumption wearable electronics.

Machine learning based models to investigate the thermoelectric performance of carbon nanotube-polyaniline nanocomposites

Thermoelectric materials have been widely recognized as a simple approach for harnessing green energy by converting thermal gradients into electrical energy. However, the intricate and conflicting interplay between electrical conductivity (σ), Seebeck coefficient (S), and thermal conductivity (k) in known materials present a challenge for improving their thermoelectric conversion efficiency. To overcome this challenge, various data-driven machine-learning techniques such as correlation matrix (CM), multiple linear regression (MLR), polynomial regression (PR), principal component analysis (PCA), and artificial neural network (ANN) have been utilized to identify the impact of different structural and compositional factors on the thermoelectric performance in carbon nanotube (CNT)-polyaniline (PANI) based nanocomposites. Our findings suggest that the thermoelectric figure of merit, (ZT=S2σκT) of these nanocomposites can be positively influenced by proper choice of doping agent of PANI and by using SWCNT, since these two parameters influence the thermoelectric outputs in the desired manner. The other input variables have conflicting impacts on the thermoelectric performance, although optimal solutions for maximized performance can be extracted. The investigation provides valuable insights about designing a PANI-CNT nanocomposite system with superior thermoelectric performance.

Enhanced thermoelectric properties of Mm-filled p-type (Fe, Co)Sb3 skutterudites via Co/Fe ratio regulation and extra Sb compensation

The band degeneracy thus thermoelectric performance of (Fe, Co)Sb3 based p-type skutterudites can be well modulated by adjusting Co/Fe ratio. Combining systematic experiments and density function theory (DFT) calculations, we revealed in this work that the variation of Co/Fe ratio could result in complicated and mutually coupled effects on the individual thermoelectric parameters (band degeneracy, band gap, Fermi level, filling limit of fillers, phonon spectrum, etc.) and that using Co/Fe ratio to improve the overall thermoelectric figure of merit is nontrivial. We eventually found that the optimal Co/Fe ratio for Mm (Misch metal) filled (Fe, Co)Sb3 lies at 1.3:2.7, which is somewhat off the Co/Fe = 1:3 point where the largest valence band degeneracy appears. Extra Sb was then introduced to compensate Sb volatilization for improved electrical transport performance. An overall peak figure of merit ZTmax of 1.06 was eventually achieved in the sample Mm0.8Fe2.7Co1.3Sb12.60, which is among the highest ones for all reported (Fe, Co)Sb3 based p-type skutterudites so far.

The thermoelectric properties of novel two-dimensional semiconductor ZrNBr alloyed with Fluorine: A DFT+U survey

In this survey, the thermoelectric properties of novel two-dimensional transition metal halide (ZrNBr) alloyed with Fluorine (F) in the replacement of Br atoms (with x = 0.5) have been studied. The density functional theory along with Hubbard’s potential has been used to study the density of states, the Seebeck coefficient, electrical conductivity, the electronic contribution of thermal conductivity, and the thermoelectric power factor. The dynamic and structural stability of the compounds has been proven by cohesive energy and phonon calculation results. By considering Hubbard’s potential of 3 eV the energy band gap of the electronic density of states has been enlarged to values of 2.73, and 2.7 eV for pure ZrNBr, and ZrNBr0.5F0.5, respectively. Moreover, the largest values of the thermoelectric power factor at room temperature (300 K) and without considering Hubbard’s potential were 29.12 × 1016 and 101 × 1016μW/m K2 s and at the negative chemical potential for pure ZrNBr, and ZrNBr0.5F0.5, respectively. While considering Hubbard’s potential, the largest peaks at 300 K were 26.42 × 1016μW/m K2 s (at positive chemical potential) and 41.41 × 1016μW/m K2 s (at negative chemical potential), for pure ZrNBr, and ZrNBr0.5F0.5, respectively. These values are in the ranges of the results for materials which are potential candidates for thermoelectric applications.

Thermoelectric properties of Ga-doped InSb alloys

Internal structure and thermoelectric properties of In1-xGaxSb alloys, prepared by melting synthesis at 1123 K, were systematically studied in this paper. Crystal structure was investigated by XRD analysis. All samples exhibited crystalline structure of single InSb phase. Transport and electrical properties were studied against temperature elevating. Electrical conductivity was determined via the standard four probe method. The thermal behavior of the electrical conductivity over the temperature range between 273 K and 473 K showed semiconducting behavior. Seebeck coefficient measurements were conducted via differential method in the temperature range 273–473 K. The measurements of Seebeck coefficient confirmed the electrical conductivity behavior of the samples. The maximum obtained Seebeck coefficient value |S| of the parent InSb compound was observed at 224 μV/K, obtained at 273 K. The alloy has been doped with Ga in order to enhance thermoelectric properties. Results showed that introducing of Ga into In sites leads to significant increase in the Seebeck coefficient up to 330.4 μV/K. Power factor was estimated from the measurements of the electrical conductivity and the Seebeck coefficient. Interesting enhancement in the thermoelectric power factor was observed with Ga-doping. The maximum power factor was obtained for the most doped sample exhibiting 2.3 μWm−1 K−2 at 273 K. The thermal conductivity was obviously reduced by substituting In with Ga. The dimensionless figure of merit was estimated showing an enhancement with the Ga addition. The maximum recorded ZT was 0.017 observed at 403 K.

Post-selenization induced structural phase transition and enhanced thermoelectric properties in AgBiSe2 alloy thin films

Thermoelectric materials have the potential to harness waste heat for energy purposes, and there is considerable scientific and technological interest in managing their thermal properties. BiAgSe2, a narrow bandgap semiconductor, is a strong candidate for use as a thermoelectric material due to its remarkably low thermal conductivity. The compound of AgBiSe2 crystallizes in the hexagonal symmetry of the grown sample at room temperature and transitions to a cubic phase, increasing the post selenization duration at 773K. The granular surface morphology has been observed and slightly decreases with increases the more post selenization treatment. The enhancement of the Seebeck coefficient value from 126 to 177 μV/K due to the phase transition, grain refinement and post-selenization treatment. The improvement of charge carrier concentration and electrical conductivity is due to improving the crystallinity and diffusion of Se atoms in the AgBiSe2 alloy thin film with post-selenization time. The maximum thermoelectric power factor (5.16 μWcm−1K−2) of stable cubic AgBiSe2 alloy thin film has been achieved at room temperature. However, the stable cubic phase of the AgBiSe2 alloy thin film exhibits excellent thermoelectric behaviour, making it a promising material for applications in thermoelectric devices.