Cellule solaire polyacetylene-sulfure de cadmium spray

SIGLECNRS T 55196 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Structural, Optical and Electrical Properties of Transparent Conducting Oxide Based on Al Doped ZnO Prepared by Spray Pyrolysis

Aluminum doped zinc oxide (AZO) thin films were deposited on glass substrates at 350 °C by spray pyrolysis technique. X-ray diffraction patterns show that the undoped and AZO films exhibit the hexagonal wűrtzite crystal structure with a preferential orientation along 2 direction. AFM images showed that AZO film with 3 % of Al has a uniform grain sizes with a surface roughness of about 24 nm. All films present a high transmittance in the visible range. Both undoped and AZO films were n-type degenerate semiconductor and the best electrical resistivity value was around 8.0 ´ 10- 2 W.cm obtained for 3 % Al content

Effect of doping on the phase stability and photophysical properties of CsPbI2Br perovskite thin films

[EN] In this study, we demonstrate that the crystallization process of CsPbI2Br films can be modulated when small amounts of additives are added to the precursor solution, leading to the formation of the bright brownish a-phase perovskite films with high orientation along the [100] crystallographic direction. Doped CsPbI2Br films exhibit improved crystallinity, with high coverage, large grain size and pinhole-free surface morphology, suitable for making high performance optoelectronic devices. We also explored the role of Cl in the photophysical properties of CsPbI2Br perovskite films using the temperature dependent photoluminescence technique. We found that the Cl ions enhance the photoluminescence emission by reducing the density of trap states, and also decrease the exciton binding energy from (22.3) meV to (11.2) meV. We believe this work contributes to understanding the effect of doping on the crystallization process with an in-depth insight into the photophysical properties of the cesium-based perovskite materials.Atourki, L.; Marí, B.; Makha, M.; Bouabid, K.; Regragui, M.; Ihlal, A.; Abd-Lefdil, M.... (2021). Effect of doping on the phase stability and photophysical properties of CsPbI2Br perovskite thin films. RSC Advances. 11(3):1440-1449. https://doi.org/10.1039/d0ra08912e1440144911

Substrate temperature optimization of pulsed-laser-deposited and in-situ Zn-supplemented-CZTS films and their integration into photovoltaic devices

The pulsed laser deposition (PLD) technique was used to deposit CZTS thin films onto SLG/Mo substrates via the KrF-laser ablation of a composite target consisting of Cu2ZnSnS4 pellet onto which Zn strips were purposely affixed. The effect of the substrate temperature (Tsub) of the PLD-CZTS films on their structure and properties was systematically studied over the 25–500 °C temperature range. The Zn content of the films was found to increase mainly when Tsub is raised from 300 to 500 °C. While both XRD and Raman analyses confirmed that the films consist of the kësterite-single-phase of which crystallinity improves when Tsub is increased (from RT up to 400 °C), the near resonant Raman (at 325 nm) revealed the presence of ZnS phase at high Tsub (> 400 °C). The optical energy band gap (Eg) of the PLD-CZTS films was consistently found to decrease from 1.9 to 1.4 eV when Tsub is increased from RT to 500 °C. Our results pointed out the Tsub = 400 °C as the optimal deposition temperature that meets at best the properties required for the PLD-CZTS films for PV application. The post-annealing (in presence of S and Sn vapors at 560 °C) of the PLD-CZTS films has improved further their crystallinity and led to the formation of some ZnS secondary phase at their surface. By appropriately integrating these post-annealed films into SLG/Mo/CZTS/CdS/ZnO/ITO photovoltaic devices, we were able to demonstrate their photoconversion ability with a PCE of 3.3 % (Voc = 512 mV, Jsc = 12.5 mA/cm2 and a FF = 51.5 %). The analysis of their EQE spectrum suggests that the effective carrier collection length in the CZTS absorption layer needs to be extended further to achieve higher photoconversion efficiencies.Peer ReviewedPostprint (author's final draft

EFFECT OF POTASSIUM CYANIDE ETCHING ON STRUCTURAL, OPTICAL AND ELECTRICAL PROPERTIES OF Cu 2 ZnSnS 4 THIN FILMS DEPOSITED BY A MODIFIED SPRAY PROCESS

International audienc

Elaboration and Characterization of Sprayed Tb-Doped ZnO Thin Films

ZnO and Tb-doped ZnO (TZO) thin films were deposited on glass substrate at 350 °C by spray pyrolysis technique. Structural, optical and electrical properties of the films were investigated as a function of dopant concentration, which was varied between 0 and 5 at % of terbium. TZO films were polycrystalline and exhibit hexagonal quartzite crystal structure with a preferential orientation along 2 direction. The AFM measurements show that the roughness of the films increased with Tb doping. All the TZO films exhibit a transmittance between 70 and 80 % in the visible range. The TZO films were n-type degenerate semiconductor with a lowest electrical resistivity of about 6.0´10- 2 W.cm

Structural Characterization of Electrodeposited Nanostructured Titanium Dioxide thin Films on Stainless Steel and on Indium Tin Oxide (ITO)

Nanostructured TiO2 thin films are fabricated directly by an anodic electrodeposition using an aqueous TiCl3 solution. TiO2 thin films were deposited on stainless steel (SS) and indium tin oxide (ITO) substrates. As deposited, all TiO2 films were amorphous. For TiO2/stainless annealed at 350 °C, XRD patterns show both anatase and rutile phases. While, only anatase phase subsists for annealing temperature at 450 °C and 500 °C. The calculated grain sizes are around 20 nm. By AFM analysis, surface root mean square (rms) roughness obtained for TiO2 /Steel is around 56 nm and decrease with annealing to 30 nm. For TiO2 thin films deposited on ITO and annealed at 350, 450, and 500 °C, only orthorhombic single phase is observed with grains size of about 25 nm. The rms of as- deposited TiO2/ITO around 60 nm decrease with annealing to 40 nm confirming that annealing process improves the roughness of the as deposited samples

SnO 2 films elaborated by radio frequency (RF)magnetron sputtering as a potential TCOs alternative for organic solar cells

International audienceTransparent conducting oxides (TCOs) are crucial component of solar cells. Tin doped indium oxide (ITO) is the most employed TCO, but the scarcity and high price of indium induce a search for lower cost TCOs with equivalent properties as substitute. Tin dioxide (SnO2) films have many advantages, such as rich sources of material, low prices, and non-toxicity. SnO2 films present a high visible light transmittance, near-infrared light reflectivity, and excellent electrical properties. They also have a higher chemical and mechanical stability compared to ITO. The aim of this work is to elaborate SnO2 films by RF-magnetron sputtering in order to use them as electrodes for Organic Solar Cells (OSCs). The SnO2 films were deposited on glass, SiO2 and quartz substrates in a mixed environment of Ar and O2. XRD measurements show that the as-deposited SnO2 films are polycrystalline with cassiterite tetragonal structure. SEM analysis showed that the films are homogeneous, continuous, and nanostructured. The electrical resistivity and average optical transmittance of the samples are about 10 −3 Ω.cm and over 80%, respectively. The estimated optical band gap (Eg) is around 4.0 eV while the work function of the films is around 5.0 eV. The SnO2 films are used as electrodes for inverted OSCs, using poly(3-hexylthiophene-2,5-diyl): [6,6]phenyl-C60-butryric acid methyl ester (P3HT:PC60BM) as active layer. The device's open circuit voltage (VOC) and short circuit current density (JSC) are similar to those obtained for the inverted OSCs employing ITO as the same electrode. Even if the achieved power conversion efficiency is lower compared to the value for the reference OSC with an ITO electrode, these results are promising and place SnO2 TCO as a potential candidate to replace ITO

The Structural and Electrochemical Properties of CuCoO2 Crystalline Nanopowders and Thin Films: Conductivity Experimental Analysis and Insights from Density Functional Theory Calculations

A novel manufacturing process is presented for producing nanopowders and thin films of CuCoO2 (CCO) material. This process utilizes three cost-effective synthesis methods: hydrothermal, sol-gel, and solid-state reactions. The resulting delafossite CuCoO2 samples were deposited onto transparent substrates through spray pyrolysis, forming innovative thin films with a nanocrystal powder structure. Prior to the transformation into thin films, CuCoO2 powder was first produced using a low-cost approach. The precursors for both powders and thin films were deposited onto glass surfaces using a spray pyrolysis process, and their characteristics were examined through X-ray diffraction, scanning electron microscopy, HR-TEM, UV-visible spectrophotometry, and electrochemical impedance spectroscopy (EIS) analyses were conducted to determine the conductivity in the transversal direction of this groundbreaking material for solar cell applications. On the other hand, the sheet resistance of the samples was investigated using the four-probe method to obtain the sheet resistivity and then calculate the in-plane conductivity of the samples. We also investigated the aging characteristics of different precursors with varying durations. The functional properties of CuCoO2 samples were explored by studying chelating agent and precursor solution aging periods using Density Functional Theory calculations (DFT). A complementary Density Functional Theory study was also performed in order to evaluate the electronic structure of this compound. Resuming, this study thoroughly discusses the synthesis of delafossite powders and their conversion into thin films, which hold potential as hole transport layers in transparent optoelectronic devices