Use of anti-solvent to enhance thermoelectric response of hybrid-halide perovskite thin films

Author(s):  
Shrikant SAINI ◽  
Izuki Matsumoto ◽  
Sakura Kishishita ◽  
Ajay Kumar Baranwal ◽  
Tomohide Yabuki ◽  
...  

Abstract Hybrid halide perovskite has been recently focused on thermoelectric energy harvesting due to the cost-effective fabrication approach and ultra-low thermal conductivity. To achieve high performance, tuning of electrical conductivity is a key parameter that is influenced by grain boundary scattering and charge carrier density. The fabrication process allows tuning these parameters. We report the use of anti-solvent to enhance the thermoelectric performance of lead-free hybrid halide perovskite, CH3NH3SnI3, thin films. Thin films with anti-solvent show higher connectivity in grains and higher Sn+4 oxidation states which results in enhancing the value of electrical conductivity. Thin films were prepared by a cost-effective wet process. Structural and chemical characterizations were performed using x-ray diffraction, scanning electron microscope, and x-ray photoelectron spectroscopy. The value of electrical conductivity and the Seebeck coefficient were measured near room temperature. The high value of power factor (1.55 µW/m.K2 at 320 K) was achieved for thin films treated with anti-solvent.

2021 ◽  
Vol 2070 (1) ◽  
pp. 012098
Author(s):  
P K Ojha ◽  
S K Mishra

Abstract Vanadium dioxides are strongly correlated systems which undergo an insulator-metal transition (IMT) from a low-temperature semiconducting phase to a high-temperature metallic phase. Among them, Vanadium dioxide (VO2) undergoes IMT close to room temperature, accompanied by a structural transition resulting change of several orders of magnitude in the electrical and optical properties. Here, we present the synthesis of VO2 by sol-gel process which employs cost-effective precursors to synthesize pure phase of VO2 thin films. The synthesized thin films were characterized using an X-ray diffraction (XRD) to confirm phase purity and high resolution scanning electron microscope (HR-SEM) to study the crystallite and particle size for the synthesized films. The film’s surface was analyzed by X-ray photoelectron spectroscopy (XPS) to determine the valence state and chemical composition of vanadium dioxide.


2010 ◽  
Vol 2010 ◽  
pp. 1-4 ◽  
Author(s):  
Bin Lv ◽  
Songbai Hu ◽  
Wei Li ◽  
Xia Di ◽  
Lianghuan Feng ◽  
...  

Deposition ofSb2Te3thin films on soda-lime glass substrates by coevaporation of Sb and Te is described in this paper.Sb2Te3thin films were characterized by x-ray diffraction (XRD), x-ray fluorescence (XRF), atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS), electrical conductivity measurements, and Hall measurements. The abnormal electrical transport behavior occurred fromin situelectrical conductivity measurements. The results indicate that as-grownSb2Te3thin films are amorphous and undergo an amorphous-crystalline transition after annealing, and the posttreatment can effectively promote the formation of Sb-Te bond and prevent oxidation of thin film surface.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Seiji Nakashima ◽  
Tohru Higuchi ◽  
Akira Yasui ◽  
Toyohiko Kinoshita ◽  
Masaru Shimizu ◽  
...  

Abstract The bulk photovoltaic effect (BPVE) is a mechanism of recent focus for novel solar cells that exceed the power conversion efficiency of p–n junction solar cells because of the quantum mechanical effect to generate photocurrent known as shift current. Ferroelectrics are receiving attention again because of their high voltage generation by the BPVE and converse piezoelectric effect to realize high performance optical actuators. We have investigated the BPVE in ferroelectric BiFeO3 (BFO) single crystal thin films, whereby the photovoltage was enhanced by Mn doping, and 852 V generation was demonstrated at 80 K. The enhancement mechanism was also investigated using soft and hard X-ray photoelectron spectroscopy (SXPES, HAXPES), and soft X-ray absorption spectroscopy with synchrotron radiation. This report reveals a way to new voltage source applications employing the BPVE for high impedance devices with ferroelectrics. Important aspects for designing ferroelectric materials by impurity doping are also discussed.


MRS Advances ◽  
2018 ◽  
Vol 3 (51) ◽  
pp. 3075-3084 ◽  
Author(s):  
Melissa M. McCarthy ◽  
Arnaud Walter ◽  
Soo-Jin Moon ◽  
Nakita K. Noel ◽  
Shane O’Brien ◽  
...  

ABSTRACTAmorphous TiO2 and SnO2 electron transport layers (ETLs) were deposited by low-temperature atomic layer deposition (ALD). Surface morphology and x-ray photoelectron spectroscopy (XPS) indicate uniform and pinhole free coverage of these ALD hole blocking layers. Both mesoporous and planar perovskite solar cells were fabricated based on these thin films with aperture areas of 1.04 cm2 for TiO2 and 0.09 cm2 and 0.70 cm2 for SnO2. The resulting cell performance of 18.3 % power conversion efficiency (PCE) using planar SnO2 on 0.09 cm2 and 15.3 % PCE using mesoporous TiO2 on 1.04 cm2 active areas are discussed in conjunction with the significance of growth parameters and ETL composition.


1994 ◽  
Vol 369 ◽  
Author(s):  
B. Wang ◽  
J. B. Bates ◽  
B. C. Chakoumakos ◽  
B. C. Sales ◽  
B. S. Kwak ◽  
...  

AbstractVarious lithium phosphorus oxynitrides have been prepared in the form of glasses, polycrystals, and thin films. The structures of these compounds were investigated by X-ray and neutron diffraction, X-ray photoelectron spectroscopy (XPS), and high-performance liquid chromatography (HPLC). The ac impedance measurements indicate a significant improvement of ionic conductivity as the result of incorporation of nitrogen into the structure. In the case of polycrystalline Li2.88PO3.73N0.14 with the γ-Li3PO4 structure, the conductivity increased by several orders of magnitude on small addition of nitrogen. The highest conductivities in the bulk glasses and thin films were found to be 3.0 × 10-7 and 8.9 × 10-7 S-cm-1 at 25°C, respectively.


Silicon incorporated carbon nano tube has been synthesized by radio frequency plasma enhanced chemical vapor deposition technique with acetylene gas. Tetraethyl orthosilicate solution was used for the synthesis of silicon incorporation in the CNT thin films. Energy dispersive X-ray analysis shows that the Si atomic percentage in the CNT thin films varied from 0 % to 3.82 %. The different chemical binding energies of carbon and silicon were analyzed from X-ray photoelectron spectroscopy spectra. In the XPS spectra, the peaks at ~531 eV, ~ 285 eV, ~151 eV and ~100 eV are the contributions from O 1s, C 1s, Si 2s and Si 2p respectively. Nanostructure morphologies of the Si-CNT thin films have been analyzed by field emission scanning electron microscopy. The length of the silicon incorporated carbon nano tubes ~100 nm and corresponding diameter ~20 nm. The increase of atomic percentage of Si in the CNT thin films, room temperature electrical conductivity increases. The electrical conductivity increase from 3.87x103 to 4.49x104 S cm-1 as the silicon atomic percentage in the CNT thin films increases from 0 to 3.82 % respectively. This study showed that the Si-CNTs thin films potentially useful in electrical application of varying its conductivity by changing the Si content independently from other parameters


Micromachines ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 2 ◽  
Author(s):  
Zelun Li ◽  
Shaojun Qi ◽  
Yana Liang ◽  
Zhenxue Zhang ◽  
Xiaoying Li ◽  
...  

Due to their relatively low cost, large surface area and good chemical and physical properties, carbon nanofibers (CNFs) are attractive for the fabrication of electrodes for supercapacitors (SCs). However, their relatively low electrical conductivity has impeded their practical application. To this end, a novel active-screen plasma activation and deposition technology has been developed to deposit silver, platinum and palladium nanoparticles on activated CNFs surfaces to increase their specific surface area and electrical conductivity, thus improving the specific capacitance. The functionalised CNFs were fully characterised using scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD) and their electrochemical properties were evaluated using cyclic voltammetry and electrochemical impedance spectroscopy. The results showed a significant improvement in specific capacitance, as well as electrochemical impedance over the untreated CNFs. The functionalisation of CNFs via environmental-friendly active-screen plasma technology provides a promising future for cost-effective supercapacitors with high power and energy density.


2002 ◽  
Vol 725 ◽  
Author(s):  
Salvador Borrós ◽  
M.Paz Diago ◽  
Joan Esteve ◽  
Núria Agulló

AbstractIn this work, thin films (thickness ∼ 0.5 μm) were obtained by plasma polymerization of pyrrole (Ppy) and thiophene (Pth) at 25-30 W and 0.1-0.2 mbar of pressure. Further doping with iodine was carried out to some of the Ppy and Pth films (Ppy/I2, Pth/I2) in order to enhance their electrical conductivity properties.Structural and morphological characterization of both Ppy and Pth as well as of Ppy/I2 and Pth/I2 was performed using Infrared Spectroscopy (IR), X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM).In the light of the information given by IR, XPS and AFM techniques, exhaustive and accurate description of both undoped and I2/doped Ppy and Pth films obtained by Plasma Polymerization is attained.


2021 ◽  
Vol 1206 (1) ◽  
pp. 012028
Author(s):  
Sk Faruque Ahmed ◽  
Mohibul Khan ◽  
Nillohit Mukherjee

Abstract Silicon incorporated carbon nanotube (Si-CNTs) thin films was prepared by radio frequency plasma enhanced chemical vapor deposition technique. Tetraethyl orthosilicate solution was used for incorporation of silicon in CNTs thin films. Energy dispersive X-ray analysis shows that the silicon atomic percentage was varied from 0 % to 6.1 %. The chemical binding energies of carbon and silicon were analyzed from X-ray photoelectron spectroscopy data. The various peaks at ~531 eV, ~ 285 eV, ~155 eV and ~104 eV was observed in the XPS spectra due to the oxygen, carbon and silicon respectively. Surface morphologies of Si-CNTs thin films have been analyzed by field emission scanning electron microscopy, which revels that the length of the silicon incorporated carbon nanotubes ~500 nm and corresponding diameter ~80 nm. The room temperature electrical conductivity was increased whereas the activation energy was decreased with the increase of atomic percentage of silicon in Si-CNTs thin films. The room temperature electrical conductivity was increased from 4.3 × 103 to 7.1 × 104 S cm−1 as the silicon atomic percentage in Si-CNTs thin films increases from 0 to 6.1 % respectively.


2019 ◽  
Vol 33 (23) ◽  
pp. 1950257
Author(s):  
R. Afrose ◽  
M. Kamruzzaman ◽  
M. N. H. Liton ◽  
M. A. Helal ◽  
M. K. R. Khan ◽  
...  

p-type conductivity and the modulation of bandgap of ZnO are crucial aspects for realization of optoelectronic devices’ applications. The Li and Li-Cu could be suitable doping agents for achieving the p-type conductivity and the modulation of bandgap of ZnO. To this point of view, the Zn[Formula: see text]Li[Formula: see text]O (x = 0 to 40 at.%) and Zn[Formula: see text]Li[Formula: see text]Cu[Formula: see text]O (fixed, x = 5 at.%, and y = 0.0 to 10 at.%) thin films were prepared on the microscopic glass substrates at a temperature of 350[Formula: see text]C using cost effective chemical spray pyrolysis (CSP) technique. Field emission scanning electron microscope images show the coexistence of interconnected fibrous and flat grains on the films surface. The grain size changes as function of Li- and Li-Cu concentrations, and at a higher doping granular grains are observed. The successful incorporation of Li and Cu-Li into ZnO crystal is confirmed by X-ray photoelectron spectroscopy (XPS) measurements. The X-ray diffraction (XRD) patterns exhibit hexagonal polycrystalline structure of doped ZnO. However, the crystallinity is deteriorated at higher Li- and Li-Cu doping concentrations. The optical bandgap study exhibits direct transition type and it is red shifted from 3.21 to 2.61 eV and 2.84 to 3.56 eV for Li and Li-Cu doping in ZnO thin films, respectively. The optical conductivity enhances as a result of Li- and Li-Cu doping in ZnO. Therefore, Li- and Li-Cu can effectively be doped to tune bandgap and enhance optical properties of ZnO for electronic and optoelectronic device applications.


Sign in / Sign up

Export Citation Format

Share Document