Influence Of Post-annealing Treatment Research Articles

Influence of post-annealing treatment on the performance of perovskite solar cells with different hole transport layers

The performance of perovskite solar cells (PSCs) is one of the key factors influencing their industrialization and market competitiveness. In this paper, post-annealing treatment, which is an effective and simple method, was used to enhance the performance of PSCs. PSCs with different hole transport layer (HTL) were prepared, and the effect of post-annealing treatment on the performance of PSCs was investigated. The results showed that post-annealing treatment could enhance the carrier extraction ability of HTL, reduce the defects in the perovskite layer, decrease non-radiative recombination, and effectively improve the device performance when PTAA was included in the HTL. After annealing treatment, it was found that the PCSs with NiOx/PTAA as the transport layer, the champion device of PSCs can achieve a PCE of 21.21 %. Compared to devices using only NiOx and PPAA as hole transport layers, the PCE increased by 36.9 % and 3 %, respectively. Meanwhile, when using NiOx/PTAA as the transport layer, compared to devices without annealing treatment, the PCE increased from 17.95 % to 21.21 %, resulting in an 18.2 % enhancement. The obtained results in this work can provide an important theoretical basis for researchers to understand the physical mechanism of post-annealing treatment on device performance and fabricate perovskite solar cells with high-performance.

Influence of Post-Annealing Treatment on Some Physical Properties of Cerium Oxide Thin Films Prepared by the Sol–Gel Method

In this study, thin films of Cerium Oxide CeO2 were fabricated using the sol–gel technique and deposited onto a glass substrate. The annealing process was carried out at various temperatures ranging from 200 to 600 °C to investigate the structural, morphological, and optical properties of the films and their interrelations. X-ray diffraction (XRD) patterns revealed the crystalline nature of the prepared films, with film quality exhibiting enhancement with increasing annealing temperature. The average crystallite size, dislocation density, microstrain, and lattice constant were determined from XRD patterns. Higher annealing temperatures were found to increase the crystallite size values from 4.71 to 15.33 nm and decrease the dislocation density and microstrain of the unit cell. Scanning electron microscope (SEM) images illustrated the uniformity of the films, presenting a spheroid shape. Optical properties such as transmittance, absorbance, reflectance, the direct band gap, extinction coefficients, the refractive index, and optical conductivity were assessed using optical measurements. The direct optical band gap of the CeO2 film was observed to decrease from 3.99 to 3.75 eV with increasing film thickness. Using the Wemple and DiDomenico (WDD) single-oscillator model, dispersion energy parameters were calculated based on the refractive index. The nonlinear optical properties of the CeO2 thin films were evaluated using these dispersion energy parameters. The improvement of optical parameters holds significance in standardizing CeO2 thin films for various optoelectronic applications.

Optoelectronic properties of electron beam-deposited NiOx thin films for solar cell application

The fabrication of highly efficient nickel oxide (NiOx) thin film for optoelectronic devices is a challenging task because optoelectronic properties are considerably influenced by deposition technique and film thickness. The effect of thickness on the film properties of electron beam–physical vapour-deposited NiOx thin film has been investigated in this work. The influence of post-annealing treatment on the optoelectronic properties of the film was compared with that of the as-deposited one. Optical transparency gradually decreased upon the successive increment in thickness of the as-deposited and annealed films. The surface roughness of as-deposited films increased linearly with the increase in film thickness, but this behaviour was altered in post-annealed films. Spherical grains with high packing density were observed on the as-deposited films, but the grain size was altered substantially on the post-annealed films. The annealed films presented a higher work function than their corresponding as-deposited films. This work presents important insights into the design of photovoltaic devices with an effective deposition process, including a high material utilisation. Moreover, an attempt of fabricating inverted perovskite solar cell on as-deposited and annealing NiOx film as hole transporting material exhibited power conversion efficiency of 11.98% and 12.28%, individually. It was noticed that the high temperature annealing on NiOx film had a very little impact on the comparative photovoltaic performance of aforementioned PSC devices.

Influence of post-annealing treatment on the morphology of Au films deposited on liquid surfaces

We report the annealing effects on the morphology of metallic films deposited on liquid surfaces, which was enabled by depositing Au atoms to a silicone oil surface by thermal evaporation at room temperature. Due to the isotropic characteristics of the liquid surface, the growth of Au films on silicone oil surfaces follows the two-stage growth model. Ramified aggregates consist of substantial nanoparticles exist in the Au film, which is different from films fabricated on solid substrates. After annealing at different temperatures, small nanoparticles started to melt first, and formed liquid layers covered on adjacent large nanoparticles. As the annealing temperature increased, more nanoparticles melt and the liquid layer became thicker, resulting in the increase of mean diameter of Au nanoparticles and film coverage. The dependence between film morphology and annealing temperature was investigated. This work provides a potential mechanism of annealing effect on the morphology of metallic films deposited on free-sustained substrates.

Influence of post-annealing treatment on dielectric and ferroelectric properties of dense BaTiO<sub>3</sub> ceramics prepared by solvothermal solidification method

Influence of post-annealing treatment on dielectric and ferroelectric properties of dense BaTiO<sub>3</sub> ceramics prepared by solvothermal solidification method

Efficiency enhancement for solution-processed PbS quantum dots solar cells by inserting graphene oxide as hole-transporting and interface modifying layer

Abstract Interface modifying between the active layer and anode solar cells is a key technique to improve the device performance. In this paper, the enhancement of power conversion efficiency (PCE) of ZnO/PbS heterojunction quantum dot (QD) solar cells Au/PbS-TBAI/ZnO/ITO was achieved by incorporating a graphene oxide (GO) layer between the PbS-TBAI active film and the Au anode. Our experimental data showed the GO interlayer was partially reduced to graphene after its post-annealing at 140 °C and it played the role of hole-transporting layer and the interface-modifying layer. In this way, the defects existed at the contact interface of PbS-TBAI/Au were reduced significantly after inserting and post-annealing GO interlayer, resulting to the enhancement of holes transport and collection efficiency, showing a PCE enhancement of 12.87% as compared to that of the control device Au/PbS-TBAI/ZnO/ITO. The influence of post-annealing treatment on the whole device, as the reduction method for GO, on the performance of the QD solar cells was also explored and discussed.

Fabrication of W-Zr-Si thin film metallic glasses and the influence of post-annealing treatment

The amorphous thin film metallic glasses (TFMGs) have been studied widely due to their unique properties and ease of fabrication as compared with the bulk metallic glasses (BMGs). Among the many TFMG systems, the W-based TFMG remains unstudied. In this work, a series of ternary W-Zr-Si TFMGs containing various W content ranging from 49.3 to 66.5at.% were fabricated using a magnetron co-sputtering system. Increasing the W content of W-Zr-Si TFMG rendered an increase of Young's modulus up to 182±4GPa with the highest W content of 66.5at.%. The film hardness was 13GPa, independent of the W concentration in the as-deposited W-Zr-Si TFMGs. The influence of post-annealing on the microstructure and mechanical properties of TFMGs was studied by a vacuum thermal treatment ranging from 450 to 750°C under various holding times. The surface roughness increased with increasing annealing temperature, with the sample annealed at the supercooled liquid region exhibited the lowest surface roughness of 1.14nm. The hardness of TFMGs increased with increasing annealing temperature and longer holding time due to annealing-induced crystallization with a highest hardness of 16.8±0.5GPa. However, the indentation toughness decreased upon annealing and the lowest value was achieved for the hardest film due to the increasing amount of short range ordered (SRO) clusters.

Straightening of chemically deposited CdS nanowires through annealing towards improved PV device performance

Cadmium sulfide (CdS) thin film consisting of nanowires over a flat CdS thin film were synthesized by depositing cadmium hydroxide [Cd(OH)2] nanowires (NW) bundles, followed by conversion to sulfide phase by using ion exchange route at room temperature (300K) based on negative free energy of formation. The influence of post annealing treatment on as-deposited CdS NW films has been studied in the temperature range 423–523K through the observation of nanowires alignments. The annealing effect on the intrinsic properties have been studied in relation with the crystallites sizes, micro strain, dislocation density and optical band gap of the deposited films. Furthermore, the behavior of inter- and intramolecular hydroxide ion (OH−) has been investigated from FTIR analysis. Additionally, the effects of post annealing on photovoltaic device performance has been scrutinized and the obtained results were correlated with structural and optical properties.

The influence of post-annealing treatment on the wettability of Ag+/Na+ ion-exchanged soda-lime glasses

In this paper, the effect of thermal annealing and the duration of ion-exchange on the wetting parameters of the Ag+/Na+ ion-exchanged glasses have been reported. The analysis of wetting angle in different post-annealing temperatures shows that the wetting angle is increased by increasing the annealing temperature. The wetting parameters of Ag+/Na+ ion-exchanged glasses at different ion-exchanged periods of time have been also investigated. Scanning electron microscopy (SEM), UV–Visible spectroscopy and Fourier transform infrared (FTIR) spectroscopy have been used for determination of surface morphology and composition analysis of the prepared samples. The results of SEM show changes in the surface of the samples for different post-annealing temperatures. The optical characterization using UV–Vis spectroscopy shows an increase in the intensity of the absorption peak with increasing the ion-exchange duration. The FTIR spectroscopy confirms the formation of silver oxide material on the surface of Ag+/Na+ ion-exchanged glasses.

The influence of post-annealing treatment on the electrical properties of In 2O 3 thin films prepared by an ultrasonic spray CVD process

Indium oxide thin films were deposited on glass substrates at different temperatures between 623 and 773 K, by an ultrasonic spray chemical vapor deposition process. The aerosol containing the precursors of the films (InCl 3·4H 2O) was transported to the reaction zone, using N 2 as carrier gas. X-ray diffraction studies showed that films are polycrystalline in nature. Typically, films as-deposited have a minimum resistivity of 2.2×10 −3 Ω cm and an optical transmission >85%. After deposition these films were subjected to many cycles of heating–cooling in air (between 300–450 K and 300–673 K). During the first one or two cycles, the maximal heating temperature was approximately 450 K, and for the following was approximately 673 K. The percentage gain in electrical conductivity after the first cycle was calculated and discussed in function of the temperature deposition of films. The activation energies were calculated.

In 2O 3 deposited by reactive evaporation of indium in oxygen atmosphere — influence of post-annealing treatment on optical and electrical properties

Transparent and conductive indium oxide films have been obtained by reactive evaporation of indium in partial oxygen pressure. The oxygen partial pressure, the substrate temperature and the deposition rate have been used as variable parameters. Post-deposition annealing treatment in air or argon ambient have also been used. During the deposition process, different mechanisms with opposite effects are in competition. Thus, oxygen vacancy density which is proportional to the carrier density decreases when the oxygen partial pressure increases, while the crystalline quality of the films improve. Therefore, an experimental domain can be defined where the films have more or less similar properties: a transmittance higher than 90% and a conductivity of 10 +3– 3×10 +3( Ω cm ) −1 . In the experimental environment, the optimal conditions used can be summarised as follows — partial oxygen pressure P 0:8×10 −2 Pa<P 0<4×10 −1 Pa ; substrate temperature T s :200 ° C<T s <250 ° C ; In 2O 3 deposition rate V d :0.05 nm s −1<V d <0.1 nm s −1 .