high-performance and flexible thermoelectric films by screen printing solution-processed nanoplate crystals - flexible film
Screen printing allows direct conversion of thermoelectric nanoparticles into flexible energy collectors and coolers.
However, obtaining flexible thermoelectric materials with a high value of ZT through printing is a daunting challenge because it is difficult to synthesize high
Poor density and conductivity of performance thermoelectric inks and printed films.
Here we show high
Performance flexible films and devices prepared by using microwave-synthesized screen printing tellur acid titanium based nano crystal inkstimulated wet-Chemical methods.
A thermoelectric film with a thickness of several tens of microns is screen printed on a flexible pi substrate and then subjected to cold pressing and sintering. The n-
The peak value of A-type film is 0.
43 and excellent flexibility, one of the highest ZT values reported in flexible thermoelectric materials.
Flexible thermal devices manufactured using printed film produce a high power density of 4.
1 mw/cm 2, the temperature difference between the hot side and the cold side is 60 °c.
The highly scalable and low-cost processes presented here for manufacturing flexible thermoelectric materials and devices provide many opportunities for the transformation of thermoelectric energy collection and cooling applications.
We used microwave-stimulated wet-synthesis of doped and functional BiTeSe pnictogen sulfur-based nanoparticles
The chemical synthesis method based on cheap organic solvent and metal salt described earlier.
In this method, by microwave stimulation, the reaction between the molecular-linked chaligen and pnictogen complexes is activated in the presence of thiamine acid (TGA)
As a shape-
Inhibition and sulfur
A mixture delivery agent.
The precipitation generated will be cleaned and dried under environmental conditions to obtain a single-
Crystal nano disk of 5-to 20-nm-
Thickness of the edge size between 50 and 500nm.
The nano-crystals dried with TGA capping agent are mixed with solvents and adhesives to produce viscous and touch-sensitive inks for screen printing.
The optimized ink contains 58 wt.
% BiSeSe nano powder, 39wt wt. % Solvent (α-
Pine alcohol from SigmaAldrich), 2u2009wt. % Binder (Disperbyk-110, from byk u. S. A. Inc. ), 1u2009wt. % Glass Frits (
From Artglass Supplies, 325 mesh).
Fully mix the ink for 20 minutes using a planetary centrifugal mixer and then use a vortex mixer for 10 minutes to get a uniform mixture. As-
The prepared ink is screen printed on a flexible pi substrate.
By controlling the screen size and repeated printing times, thermoelectric films of different thickness in the range of 10-100 μm were obtained.
The printed film is first dried on the hot plate in the air at 200 °c to remove the solvent and the adhesive, and then cold pressed with a hydraulic press to solidify the film.
In order to remove the TGA surface active substance and further increase the film density, the film was finally vacuum-sintering for 45 minutes at 430 °c.
Although better thermoelectric properties can be obtained at higher sintering temperatures, the sintering temperature remains below the melting point of the pi substrate. Temperature-dependent in-
The plane conductivity and Seebeck coefficients of the film samples were measured simultaneously using commercial Linseis Seebeck and resistivity instruments.
The above two properties of the same sample are also measured using household instruments
The test system is built, and the two sets of measurement results are within 2%.
In order to measure the thermal conductivity of the sample, an independent film with a thickness of about 100 μm was prepared under the same conditions as the thinner film was prepared on the substrate.
The plane thermal diffusion coefficient of the independent film was measured using a laser flash meter. The cross-
The sample density measured using the Archimedes method and the specific heat measured using the DSC instrument are then used to determine the plane thermal conductivity. The in-
Using steady state-directly measure the plane thermal conductivity of the independent film
State method in vacuum, which is located within 5% of the Cross
It is indicated that the sample is of the same sex.
Detailed information about the measurement of thermal conductivity is included.
Carrier concentration and mobility were measured using Hall measurements performed on a physical characteristic measurement system (PPMS)
4 wire connection, magnetic field sweep from 1 t to 1 t.
Five 10mm x 2mm x 0. 01u2009mm n-
Print the BiTeSe type element on a flexible pi substrate with a spacing of 4mm.
To connect thin copper foil in series, weld it to five elements.
A custom test bed was built using two commercial Peltier modules, one as a heater and the other as a cooler.
Thermal side and cold side thermal grounding of TE devices to two Peltier modules to produce a temperature gradient.
75 µm in diameter K-2
Install the type thermocouple on the hot and cold side of the device to measure the temperature difference.
The device is connected in series with shunt resistors and variable resistors for impedance matching at each measurement temperature.
Measure the open voltage, load voltage, current, internal resistance and power output of the device at each hotspot
Side temperature when cold-
The side temperature remains constant.