temperature, crystalline phase and influence of substrate properties in intense pulsed light sintering of copper sulfide nanoparticle thin films - transparent polycarbonate sheet
Intense pulsed light sintering (IPL)
Sintering nanoparticles using pulsed visible light (NPs)
Film for functional equipment.
Although the IPL of the sulfur compound NPs is shown, the work is limited in predicting the crystal phase of the film and the impact of the optical properties of the substrate.
Here, we describe and simulate the evolution of the film temperature and crystalline phase of the sulfur family hydrogen sulfide NP film on the glass during the IPL process.
Within 2-7 seconds, the film recrystals as crystalline covellite and digenite phases at 12-6 °c and 15-15 °c, respectively. Post-
Color film with p-
Type behavior, low resistivity (~10−3–10−4u2009Ω-cm)
, Similar visible transmission and lower near
IR transmission compared to-deposited film.
The thermal model was verified by experiments and combined with the thermodynamic method predicted by crystal phase, and the influence of substrate film transmission force and optical properties on heating was considered during the IPL process, thus extending
The model is used to display-
A priori controls the IPL parameters, taking into account both the thermal and optical properties of the film and the substrate, in order to obtain the desired crystal phase during the IPL process of such films on paper and pc substrates. Rapid low-
Temperature sintering of nanoparticles (NPs)
Large-Area films and patterns are of great interest in expanding the manufacture of functional devices on rigid and flexible substrates.
Compared with the existing NP sintering methods (oven-
Based on sintering, rapid heat, laser, microwave and electricity)
Intense pulsed light sintering (IPL)
The process has large concurrency-area (e. g.
, ≥ 12x0. 75 inches here)and high-
IPL uses pulse, Width-spectrum (350–750u2009nm)
Light emitted by xenon lamps for Sintering metal (Ag, Cu)
And semiconductor sulfur compounds (
CdS, cadmium, CIGS, CZTS)NPs.
Copper sulfide (Markus, x = month 1, month)is an earth-
Rich sulfur compounds, thus cheaper and less toxic than many other sulfur compounds (e. g. , CdS and CdTe).
The use of CuS films was found in transistors, switches, lithium-ion batteries, electro-optic devices and solar control window coatings.
CuS NP film was also synthesized by vacuum.
Solution based on method
Deposition methods based on nanoparticles, such as chemical bath deposition, can achieve simpler operation, lower cost and lower deposition temperature.
However, NPs deposited is usually required
Deposition sintering to obtain clear crystal phases and required optics-
Electronic properties of the above applications.
Past work on the metal NPs IPL has carried out experiments and modeling to predict temperature evolution. Chung .
Monitor the conductivity changes during the IPL using the Wisden Bridge to find the best IPL parameters for silver NPs.
This method is extended by measuring the temperature using a thermocouple embedded in the film.
Based on the thermal model of the heat transfer equation, the optical absorption degree of the film is used as the heat source, and the convection and radiation loss to the environment are verified according to the experimental temperature evolution.
Unlike the model of laser sintering, this method accounts for a wide range
Spectral properties of xenon lamp light. Bansal . showed a self-
The limiting behavior during the IPL of Ag NPs is due to the gradual decrease of optical absorption with the increase of density, resulting in a turning point in temperature evolution during the IPL.
Past studies of CdS IPL have shown that due to the fusion and sintering of NPs and-deposited film.
However, the crystal phase did not change after IPL.
Although the increase in the degree of crystalline was observed, the crystal structure of either the cadmium-cadmium NP film or the perovskite NP film did not change.
The application of IPL in CIG metal alloy and Se NP composite film has been prepared for Cu (In,Ga)
Se Film was prepared by NP melting base alloy method, involving physical phase transition.
Temperature evolution modeling in the IPL process of CdS NP film on glass uses a similar method to predict temperature evolution as a function of the IPL parameter.
In these work, although the crystal size increases due to IPL, the crystal structure changes little or no, and this no longer requires crystal phase prediction.
Sulfur compounds like CuS have many forms that can change the crystal phase (
As shown in this work)
During the IPL, the performance of the film changes accordingly.
In addition, the above model does not believe that the xenon light transmitted through the film is the heat source on the film
If the film is thin enough and there is obvious transmission (
This is the case here)
And use an opaque or translucent substrate (e. g. paper)
Then this heat source can affect the temperature rise and crystal phase transition of the film.
In addition, the existence or non-existence of the self
The limiting behavior seen in the IPL of the metal NPs has not been confirmed in the IPL of the sulfur compounds.
Compared to the traditional thermal models used in the literature, models used to predict temperature evolution need to be different if there is a coupling between the crystal phase and NP compaction and optical absorption.
This work focuses on experimental representation and simulation of the evolution of temperature and phase transition, especially in the IPL process of CuS NP films, where the crystal structure of CuS changes to different polycrystals.
The evolution of the film temperature during the film IPL process on the glass substrate measured by the experiment is related to the crystal phase, morphology, electrical properties and optical properties of the film after IPL.
This temperature evolution is also used to observe the existence or absence of itself.
Limit behavior during IPL.
Based on these observations, a thermal model is used to simulate the temperature evolution and is extended as follows.
First of all, the Experimental derivation of the film phase evolution only method, the evolution of temperature is associated with the change of the film phase content.
Secondly, the extended thermal model considers the non-
The negligible transmission ratio of the copper-sulfur membrane and the secondary heat source resulting from it is produced on the membrane-
The substrate interface when using an opaque substrate, such as paper.
Through experimental measurements, the temperature prediction was quantitatively verified, and then the extended model was used to understand the temperature evolution and crystal phase transition of CuS NP films on paper and pc substrates during the IPL process.
The effects of these observations on the scalability of the CuS film IPL and the customization of the IPL parameters when using a substrate with different optical and thermal properties are discussed.
The experimental and computational methods used are briefly described here, and a more detailed discussion is carried out in the method section.
Hydrogen sulfide NP film was deposited on 1mm thick 2. 54u2009cmu2009×u20091.
After Vas-, 9 cm glass substrate was obtained by chemical bath depositionUmnuay . (
Details in supplementary discussion).
The IPL is set by a pulse xenon flash (
Xenon company Sinteron 3000)
And hot camera (
TIM 200, maximum temperature 16 °c)
Used to measure Film temperature.
The response time of this camera is high (8 kbps ms frame rate)than the on-
Time of xenon lamp.
In order to be as close as possible to measuring the peak temperature of each pulse, the temperature measurement began long before the xenon lamp flashing, and 5 different samples were measured in a random way.
The temperature shown here comes from at least 3 samples that are most consistent with each other, with a standard deviation of no more than 10-15% per pulse peak temperature.
Also, since the closure
The time is in milliseconds, and the worst error to miss the peak temperature may be in the first pulse.
The IPL pulse flux, duty cycle and pulse number are different (Table).
The amount of pulse injection varies at 5, 7.
J/cm 5, 10 and 15.
Since in the process of heating and cooling, in addition to the temperature, the phase change can also be a function of the heating and cooling time, the duty cycle of the two pulses is 0. 08% and 0.
15% used with 5 IPL pulses per injection.
The change in duty cycle is through a constant on-
Time and Change-
Time, understand the role of cooling time (off time).
Irradiance, I. e. , (
Amount of note in the table/on time)
It is constant at 6. 9u2009kW/cm.
Additional experiment 0 with two IPL pulses.
All pulses in the table also perform a 15% duty cycle.
Representative optical image of-
Storage and mailing
The picture shows the IPL movie. . Cross-
Segmented scanning electron microscope (SEM)
Used to characterize the microscopic form and thickness of the film.
Atomic force microscope (AFM)
Energy dispersion spectrum (EDS)
And grazing rates
Ray diffraction (GIXRD)
It is used to determine the roughness, element composition and crystal phase of the film.
The optical transmission ratio, reflection ratio and absorption ratio are obtained using a splitter equipped with an integral sphere.
Use Signatone four-measure the square resistance
Point probe and use with film thickness to obtain bulk resistivity.
Hall measurements are used to characterize the concentration and mobility of charge carriers in the film.
A thermal finite element model is implemented in COMSOL, which consists of a 15 nm thick CuS film on a 1mm thick glass substrate (Fig. )
Conductive loss is allowed between the film and the substrate.
The film thickness and volume are obtained from the thickness and deposition area measured by the experiment, and for the sake of simplicity, the shrinkage in the IPL process is ignored, as has been done in the past.
The average room temperature value obtained from the literature fixes the thermal properties of the film and substrate (
See supplementary form).
The glass substrate is modeled as an infinite unit layer of thickness, and the bottom of the substrate is insulated, as in our experiment.
Since the surface area on the top of the film is much larger than the surface area of the side wall, only the convection loss on the top surface of the film is considered, and the symmetric boundary condition is used on the side wall of the film.
The optical absorption of the film in the energy spectrum of xenon lamps and its evolution in the IPL process were obtained.
The temperature evolution of the predicted and experimental measurements in four cases was compared, that is, 5 pulses with a duty cycle of 0. 15% and 0.
08% and injection E1 and e4.
The condition of optical opaque paper and transparent polycarbonate substrate with the same thickness as the glass substrate is also simulated, and the substrate has appropriate thermal properties (
See supplementary form).
For opaque paper, xenon light transmitted through the CuS film will directly heat the surface of the paper.
Therefore, the film transmission observed in the experiment is used together with the energy of the incident lamp and the xenon lamp spectrum to add a boundary heat source to the film.
Paper interface (Fig. ).
For IPL experiments performed on glass substrates, quantitative measurements of phase evolution have been developed from gix measurements, in relation to the dissipated energy in the film, and used to understand the film phase evolution in the process of IPL on the paper and pc substrate.