Low-bandgap copolymers consisting of 2,1,3-benzoselenadiazole and carbazole derivatives with thiophene or selenophene π-bridges

Two donor–acceptor-type alternating copolymers consisting of 2,1,3-benzoselenadiazole and carbazole derivatives with thiophene or selenophene π-bridges were synthesized by Suzuki cross-coupling polymerization, and their optical, electrochemical, and photovoltaic properties were compared. The selenophene π-bridged copolymer (PCz-DSeBSe) exhibited a smaller band-gap (1.82 eV) than the thiophene-bridged polymer (PCz-DTBSe; 1.89 eV). PCz-DSeBSe also showed a deeper highest occupied molecular orbital energy level (−5.36 eV) than PCz-DTBSe (−5.20 eV). Moreover, the PCz-DSeBSe thin film showed higher crystallinity and hole mobility than the PCz-DTBSe thin film. Organic photovoltaic devices were fabricated using the polymers as the donors and [6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₁BM) as the acceptor. The device using PCz-DSeBSe showed a higher open circuit voltage (V_oc), short circuit current density (J_sc), and power conversion efficiency (PCE) than that using PCz-DTBSe. The fabricated indium tin oxide/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/PCz-DSeBSe:PC₇₁BM/LiF/Al device showed the maximum PCE of 2.88% with a J_sc of 7.87 mA/cm², an V_oc of 0.80 V, and a fill factor of 0.50 under AM 1.5G irradiation (100 mW/cm²).     

Chemical and interfacial design in the visible-light-absorbing ferroelectric thin films

Ferroelectric thin films with switchable polarization and anomalous photoelectric effects have received extensive attention recently. However, the improvement of photoelectric performance is accompanied by the weakening of ferroelectricity. Here, both chemical and interlayer design are used to regulate the polarization and optical properties of BiFeO₃-based ferroelectric films. We achieved an improvement in both ferroelectricity and bandgap by chemical composition. The remanent polarization has been enhanced to 73.8 μC/cm² from 0.2 μC/cm², ascribed to the structural transition. The band gap of Eu-BiFeO₃ films has been reduced to 2.23 eV from 2.42 eV due to the unique energy level from Eu 4f, indicating the enhanced visible-light-absorbing capability. We have designed a "sandwich" interfacial structure of homogeneous Eu-BiFeO₃ films. A clever combination between optimal ferroelectricity and narrow band gap with near Eu contents of BFO films would generate an interfacial layer with a homogeneous gradient component, which should favor the switching of ferroelectric domains. The results show that the remanent polarization improved by 17 % to 86.2 μC/cm² while the band gap has also improved. Intriguingly, the short-circuit current density (J_sc) and open circuit (V_oc) of the photovoltaic signal of the optimal films are 89.0 nA and 0.412 V, respectively. This provides a simple and intelligent way to design the ferroelectric-photoelectric thin films and lays the foundation for optical information storage devices.     

Enhanced switchable ferroelectric photovoltaic in BiFeO3 based films through chemical-strain-tuned polarization

Ferroelectric photovoltaic (FE-PV) materials have generated widespread attention due to their unique switchable photovoltaic behavior, but suffering from low photocurrent and remanent polarization. Herein, enhanced ferroelectric polarization and switchable photovoltaic in BiFeO₃ based thin films were achieved by the optimization of Bi content. The compact and uniform films with few defects were obtained by the control of chemical composition. The remanent polarization increased from 3.4 to 73.9 μC cm^?2 showing a qualitative leap. Intriguingly, the control range of photovoltaic signal between two polarization directions of the short-circuit current density (J_SC) and open circuit (V_OC) in present films exhibited an increase of 99.2% and 278.9%, respectively. It is suggested that the ferroelectric polarization was the main driving force for enhancing switchable ferroelectric photovoltaic. Therefore, the present work outstands a simple idea to enhance switchable ferroelectric photovoltaic based on the chemical engineering, providing a promising pathway for the development of photovoltaic devices.     

Effect of composition and grain size on dielectric,ferroelectric and induced strain behavior of PLZT/ZrO2 composites

Lead lanthanum zirconate titanate ceramics (PLZT) are well known for their excellent dielectric, piezoelectric and ferroelectric properties. In this study, PLZT 9/70/30, 9/65/35 and 9/60/40 ceramics were prepared by vibro-milling mixed-oxide method. All compositions of powders were uniaxial pressed in pellets and sintered at the temperatures of 1200–1275 °C with various soaking times of 2, 4 and 6 h. The X-ray diffraction (XRD) patterns confirmed that all the PLZT samples had perovskite structure with ZrO₂ as a second phase and PLZT/ZrO₂ composite structure was formed. Dielectric behavior at the frequency of 1 kHz showed broad peak indicating relaxor ferroelectric behavior and the difference of the temperature at maximum dielectric at different frequencies increased when Zr:Ti ratio increased. Polarization with electric field (P-E loop) at room temperature showed that when Zr:Ti ratio increased, the coercive field decreased resulting from crystal structure change from tetragonal to rhombohedral. Induced strain with electric field depended on microstructure where the value of S_max/E_max tended to decrease with increasing grain size. It can be concluded that dielectric and ferroelectric behavior predominantly depended on composition of PLZT ceramics and induced strain behavior predominantly depended on grain size of PLZT ceramics.     

A new series of random conjugated copolymers containing 3,4-diphenyl-maleimide and thiophene units for organic photovoltaic cell applications

A series of random conjugated copolymers (labeled PMLTQT, PMLT2T, and PMLT3T) consisting of 3,4-diphenyl-maleimide and various thiophene derivatives has been designed and synthesized via Stille cross-coupling for application in polymer solar cells. These copolymers were readily soluble in common organic solvents, thermally stable from 405 to 437 °C upon heating, and exhibited good absorption in the UV and visible regions from 300 to 650 nm. The intensities of the PL emission spectra of these copolymers in a solid film were dramatically quenched by the addition of 50 wt% [6,6]-phenyl C₆₁ butyric acid methyl ester (PC₆₁BM). Their electrochemical properties indicated that the highest occupied molecular orbital levels of these copolymers were in the range of ?5.63–5.73 eV, characteristic of better air stability and a high open-circuit voltage (V_oc) suitable for application to photovoltaic cells. Bulk heterojunction photovoltaic devices composed of an active layer of electron-donor copolymers blended with the electron acceptor PC₆₁BM or [6,6]-phenyl C₇₁ butyric acid methyl ester (PC₇₁BM) at a weight ratio of 1:3 were investigated. The photovoltaic device containing PMLT3T and PC₇₁BM (1:3, w/w) as the active layer afforded the best performance among these copolymers, with a V_oc of 0.74 V, J_sc of 7.4 mA cm^?2 and a PCE of 1.20% under AM 1.5 G simulated solar light.     

Electrical and photovoltaic properties of Pb/trans- (CH)x and Pb/[CH(AsF5)y]x schottky barriers

The rectifying and photovoltaic properties of Pb/trans-polyacetylene/graphite sandwich cells have been examined. The dependence of the short-circuit current density (J_sc) and open-circuit voltage (V_oc) on light intensity have been determined. Some data on a Pb/AsF₅ lightly doped polyacetylene graphite cell are also reported.     

Effect of chlorination and fluorination of benzothiadiazole on the performance of polymer solar cells

In order to explore the effects of chlorine and fluorine on photophysical properties and the differences, in this work, we synthesized five new polymers, P1 – P5 , in which benzo[1,2-b:4,5-b]dithiophene as the electron donating and benzothiadiazole as electron withdrawing. Analysis of these five polymers showed that the introduction of Cl and F atoms can deeper the highest occupied molecular orbital of these polymers and enhance the absorption of light by the species, thereby improving V_oc and J_sc. Chlorination has a stronger ability to reduce energy levels and broaden the absorption spectrum compared to fluorination. Among them, P2 showed an efficiency of 4.08% with J_sc of 11.28 mA/cm², V_oc of 0.79 V, and fill factor (FF) of 0.45. Since chlorination is easier than fluorination in terms of synthesis, it is advantageous for practical applications. Therefore, we think that chlorination should not be ignored when designing high efficiency photovoltaic materials, especially when their fluorinated counterparts have proven to have good properties.     

Enhancement of photovoltaic properties in supramolecular polymer networks featuring a solar cell main-chain polymer H-bonded with conjugated cross-linkers

Stille polymerization was employed to synthesize a low-band-gap (LBG) conjugated main-chain polymer PBTH consisting of bithiazole, dithieno[3,2-b:2′,3′-d]pyrroles (DTP), and pendent melamine derivatives. Novel supramolecular polymer networks PBTH/C and PBTH/F were developed by mixing proper molar amounts of polymer PBTH (containing melamine pendants) to be hydrogen-bonded (H-bonded) with complementary uracil-based conjugated cross-linkers C and F (i.e., containing two symmetrical uracil moieties connected with carbazole and fluorene units through triple bonds). The formation of multiple H-bonds between polymer PBTH and cross-linkers C or F was confirmed by FT-IR measurements. In contrast to polymer PBTH, the supramolecular design with multiple H-bonds can enhance the photovoltaic properties of polymer solar cell (PSC) devices containing H-bonded polymer networks PBTH/C and PBTH/F by tuning their light harvesting capabilities, HOMO energy levels, and crystallinities. Initially, the power conversion efficiency (PCE) values of PSC devices containing supramolecular polymer networks PBTH/C and PBTH/F as electron donors and [6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₀BM) as an electron acceptor (polymer:PC₇₀BM = 1:1 w/w) are found to be 0.97 and 0.68%, respectively, in contrast to 0.52% for polymer PBTH. The highest PCE value of 1.56% with a short-circuit current densities (J_sc) value of 7.16 mA/cm², a open circuit voltages (V_oc) value of 0.60 V, and a fill factor (FF) of 0.36 was further optimized in the PSC device containing a supramolecular polymer network PBTH/C as polymer:PC₇₀BM = 1:2 w/w. These results indicate that supramolecular design is an effective route towards better photovoltaic properties of V_oc, J_sc, and PCE values in polymer solar cells.     

Greatly enhanced photocurrent in inorganic perovskite [KNbO3]0.9[BaNi0.5Nb0.5O3‐σ]0.1 ferroelectric thin‐film solar cell

Inorganic perovskite [KNbO₃]_0.9[BaNi_0.5Nb_0.5O_3‐σ]_0.1 (KBNNO) ferroelectric thin films with narrow band gap (1.83 eV) and high room‐temperature remnant polarization (Pr = 0.54 μC/cm²) was grown successfully on the Pt(111)/Ti/SiO₂/Si(100) substrates by pulsed laser deposition. Ferroelectric solar cells with a basic structure of ITO/KBNNO/Pt were further prepared based on these thin films, which exhibited obvious external‐poling dependent photovoltaic effects. When the devices were negatively poled, the short‐circuit current and open‐circuit voltage were both significantly higher than those of the devices poled positively. This is attributed to enhanced charge separation under the depolarization field induced by the negative poling, which is superimposed with the built‐in field induced by the Schottky barriers at the interfaces between KBNNO and the two electrodes. When a poling voltage of ‐1 V was applied, the device showed a short‐circuit current as high as 27.3 μA/cm², which was by two orders of magnitude larger than that of the KBNNO thick‐film (20 μm) devices reported previously. This work may inspire further exploration for lead‐free inorganic perovskite ferroelectric photovoltaic devices.     

Enhanced electrical and photocurrent characteristics of sol-gel derived Ni-doped PbTiO3 thin films

Partial substitution of group 10 metal for titanium is predicted theoretically to be one of the most effective ways to decrease the band gap of PbTiO₃-based ferroelectric photovoltaic materials. It is therefore of interest to experimentally investigate their ferroelectric and photovoltaic properties. In this work, we focus on the electrical and photocurrent properties of Ni-doped PbTiO₃ thin films prepared via a sol-gel route. The nickel incorporation does not modify the crystalline structure of PbTiO₃ thin film, but it can increase the dielectric constant, ferroelectric polarization and photocurrent, and simultaneously decrease the band gap. The maximum remnant polarization (P_r) of 58.1 μC/cm² is observed in PbTi_0.8Ni_0.2O₃ thin film, and its photocurrent density is improved to be approximately one order larger than that of PbTiO₃ thin film and simultaneously exhibits the polarization-dependent switching characteristic, which may be a promising choice for ferroelectric photovoltaic applications.     

Low bandgap EDOT-quinoxaline and EDOT-thiadiazol-quinoxaline conjugated polymers: Synthesis, redox, and photovoltaic device

Three new low bandgap conjugated copolymers with 3,4-ethylenedioxythiophene (EDOT) as donor and 2,3-bis(4-octyloxyphenyl)-quinoxaline (P1), 2,3-bis(4-octyloxyphenyl)-thiadiazol-quinoxaline (P2, P3) as acceptors were synthesized by Stille cross-coupling reaction, and their optical and electrochemical properties were studied. These polymers exhibited optical bandgap of 1.77, 1.29 and 1.13 eV, for P1, P2 and P3, respectively. Photovoltaic cells with device configuration of ITO/PEDOT: PSS/Copolymer: PCBM (1:4 w/w)/LiF/Al were fabricated. The measurements revealed an open-circuit voltage (V_oc) of 0.52 V, short-circuit current density (J_sc) of 3.24 mA/cm² and power conversion efficiency (PCE) of 0.60% for P1, and showed a V_oc of 0.33 V, J_sc of 2.11 mA/cm², PCE of 0.39% for P2.     

Dielectric,ferroelectric and induced strain behavior of PLZT 9/65/35 ceramics modified by Bi2O3 and CuO co-doping

PLZT 9/65/35 (Pb_0.91La_0.09(Zr_0.65Ti_0.35)_0.9775O₃) ceramics with addition of 0.25, 0.5 and 1.0 wt% of Bi₂O₃/CuO (where the ratio of Bi₂O₃:CuO=9:1 by mole) were prepared by sintering at the temperatures between 1000 and 1200 °C. It was found that Bi₂O₃/CuO could bring the sintering temperature down ~50 °C to obtain PLZT with no second phase. Dielectric and ferroelectric properties were investigated. Bi₂O₃/CuO decreased both coercive field and remnant polarization, which was caused by an increase of the degree of diffuseness in relaxor ferroelectric materials. Electric field induced strain behavior was also investigated and it was found that the addition of Bi₂O₃/CuO increased the maximum induced strain and maximized electrostrictive effect. Therefore, Bi₂O₃/CuO was useful as a sintering aid, which improved the dielectric and the relaxor ferroelectric properties as well as the electric field induced strain of PLZT ceramics.     

Enhanced photovoltaic properties of PbTiO3-based ferroelectric thin films prepared by a sol-gel process

PbTiO₃ (PTO), Pb(Mn_0.1Ti_0.9)O₃ (PMTO), Pb(Sr_0.1Ti_0.9)O₃ (PSTO), and Pb(Zr_0.1Ti_0.9)O₃ (PZTO) were prepared on an indium tin oxide (ITO)/glass substrate by a sol-gel method. PTO, PMTO, PSTO, and PZTO films exhibited energy band gaps of 3.55 eV, 3.63 eV, 3.59 eV, and 3.66 eV, respectively. All these films generated high photocurrents due to high shift currents, because carrier migration channels were successfully introduced by a lattice mismatch between the films and ITO substrates. The PMTO thin film exhibited the best ferroelectric and photovoltaic properties, with a photovoltage of 0.74 V, a photocurrent density of 70 μA/cm², and a fill factor of 43.34%, which confirms that shift current and ferroelectric polarization are two main factors that affect the ferroelectric photovoltaic properties. The PSTO, PZTO, and PTO thin films displayed space-charge-limited current (SCLC) when the electric field strength was below 10 kV/cm, and these three films broke down when the electric field strength was above 10 kV/cm. Analysis of the shift current mechanism confirmed that the breakdown of the PZTO and PSTO thin films resulted from Pool Frenkel emission current. The PMTO thin film displayed SCLC in the test range, which indicates that doping with Mn could inhibit defect formation in ferroelectric thin films.     

Ferroelectric nanodot formation from spin‐coated poly(vinylidene fluoride‐co‐trifluoroethylene) films and their application to organic solar cells

We demonstrated a facile route to the preparation of self‐assembled poly(vinylidene fluoride‐co‐trifluoroethylene) [P(VDF‐TrFE)] nanodots from spin‐coated thin films. We found that the initial film thickness would play an important role in the formation of such P(VDF‐TrFE) nanodots. Interestingly, the electric dipoles of such nanodots were self‐aligned toward the bottom electrode and their ferroelectric properties were determined by using piezoresponse force microscopy. In addition, the self‐polarized ferroelectric nanostructures were introduced to small molecular organic photovoltaic devices and allowed for enhancing the short circuit current density (J_sc) from 9.4 mA/cm² to 10.2 mA/cm² and the power conversion efficiency from 2.37% to 2.65%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41230.     

Influence of iodine concentration on the photoelectrochemical performance of dye-sensitized solar cells containing non-volatile electrolyte

The effect of iodine concentration in the electrolyte with non-volatile solvent of dye-sensitized solar cells (DSCs) on photovoltaic performance was studied. The electron transport and interfacial recombination kinetics were also systematically investigated by electron impedance spectroscopy (EIS). With the iodine concentration increased from 0.025 to 0.1 M, open-circuit voltage (V_oc) and photocurrent density (J_sc) decreased while fill factor (ff) increased significantly. The decline of the V_oc and J_sc was mainly ascribed to increased electron recombination with tri-iodide ions (I₃⁻). The increased fill factor was primarily brought by a decrease in the total resistance. From impedance spectra of the solar cells, it can be concluded that increasing the iodine concentration in electrolytes could decrease charge transfer resistance (R_ct) and the chemical capacitance (C_μ), increase the electron transport resistance (R_t), and hence decrease the electron lifetime (τ) and the effective diffusion coefficient (D_n) of electrons in the TiO₂ semiconductor. With optimum iodine concentration, device showed a photocurrent density of 16.19 mA cm⁻², an open-circuit voltage of 0.765 V, a fill factor of 0.66, and an overall photo-energy conversion efficiency of 8.15% at standard AM 1.5 simulated sunlight (100 mW cm⁻²).     

Optoelectronic properties of nitrogenated amorphous carbon films synthesized by microwave surface wave plasma chemical vapor deposition system

The n-type nitrogen doped amorphous carbon (a-C:N) thin films have been grown by microwave (MW) surface wave plasma (SWP) chemical vapor deposition (CVD) system on silicon, quartz and ITO substrates at different nitrogen flow rates (1 to 4 sccm). The effects of nitrogen doping on chemical, optical, structural and electrical properties were studied through X-ray photoelectron spectroscopy, Nanopics 2100/NPX200 surface profiler, UV/VIS/NIR spectroscopy, Raman spectroscopy and solar simulator measurements. Argon, acetylene and nitrogen are used as plasma sources. Optical band gap decreased and nitrogen atomic concentration (%) increased with increasing nitrogen flow rate as a dopant. The a-C:N/p-Si based device exhibits photovoltaic behavior under illumination (AM 1.5, 100 mW/cm²), with a maximum open-circuit voltage (V_oc), short-circuit current (J_sc) and fill factor of 4.2 mV, 7.4 μA/cm² and 0.25 respectively.     

Synthesis and properties of a new conjugated polymer containing benzodithiophene for polymer solar cells

We have synthesized a new conjugated polymer PBDTDT containing 4,8-dioctyloxybenzo[1,2-b;3,4-b′]di-thiophene and 2,2′-dithiophene via a Stille coupling reaction. The copolymer was characterized by FTIR, NMR, GPC, TGA, DSC, UV–vis absorption, and electrochemical cyclic voltammetry. TGA showed that the copolymer exhibited good thermal stability. The optical, electrochemical, photovoltaic properties, and hole mobility of the copolymer were investigated and discussed. As a result, the polymer solar cell based on PBDTDT with a conventional device configuration of ITO/PEDOT:PSS/PBDTDT:PC₆₁BM/LiF/Al showed a power conversion efficiency of 1.19 %, with a short-circuit current density (J _sc) of 4.72 mA/cm², an open-circuit voltage (V _oc) of 0.6 V and a fill factor of 53.3 % under the AM 1.5G illumination with an intensity of 100 mW/cm² from a solar simulator.     

Effect of electric poling on structural,magnetic and ferroelectric properties of 0.8PbFe0.5Nb0.5O3-0.2BiFeO3 multiferroic solid solution

The effect of electric poling on structure, magnetic and ferroelectric properties of 0.8PbFe_0.5Nb_0.5O₃-0.2BiFeO₃ (0.8PFN-0.2BFO) multiferroic was studied through XRD, Raman, magnetic and ferroelectric measurements. Single step solid state reaction method was adopted to synthesize single phase 0.8PFN-0.2BFO multiferroic at lower calcination and sintering temperature. Room temperature (RT) XRD pattern before and after poling confirmed the monoclinic structure with Cm space group. Rietveld refined XRD for poled and unpoled sample shows the influence of electric poling on Fe-O1, Fe-O2, Nb-O and Bi-O modes. There is a small variation in the lattice parameters after electric poling. The structural properties were also studied in detail for the poled and unpoled 0.8PFN-0.2BFO using Raman spectroscopy. Raman measurements were carried out over a wide range of temperature (250–550 K) for both poled and unpoled samples. At RT unpoled 0.8PFN-0.2BFO multiferroic exhibit 8 active modes at 211, 263, 440, 484, 571, 706, 785 and 1120 cm^-1 in the frequency range 100–1200 cm^-1. The Raman peaks exhibits significant changes in intensity as well as shape of the spectra at the characteristic temperature T_C (470 K) and T_N (310 K). Poled Raman spectra show major changes in the Fe/Nb-O modes intensities around T_N and are due to dynamic nature of spin phonon coupling. Changes observed in the temperature dependent magnetic measurements i.e. ZFC/FC and M − H loop evidence the existence of converse magneto-electric coupling (CME) and this is due to the poling effects on Fe-O, Nb-O active modes. Due to rotation of the oxygen octahedral the electric field induced strain will originate in the system. P-E loops after poling show an increase in remnant polarisation and coercive field due to an improvement in domain ordering. The potential tunability of magnetisation with electric poling is an ideal tool for realisation of application in practical devices.     

New diketo-pyrrolo-pyrrole (DPP) sensitizer containing a furan moiety for efficient and stable dye-sensitized solar cells

A new metal-free organic sensitizer containing a furan moiety as the π-spacer based on the diketo-pyrrolo-pyrrole unit was synthesized through simple synthetic routes and with low cost for the application of dye-sensitized solar cells. Two corresponding dyes with benzene and thiophene spacers were also synthesized for the purpose of comparison. On the basis of optimized DSSC test conditions, the sensitizer containing the furan shows prominent solar energy conversion efficiency (η) of 5.65% (J_sc = 15.96 mA cm⁻², V_oc = 541 mV, ff = 0.65) under simulated full sunlight irradiation. The dyes were also tested in a solvent-free ionic liquid electrolyte devices and the stability of devices was performed over 2000 h at full sunlight. The sensitizer containing the furan moiety exhibited good stability and better photovoltaic performance of up to 4.41% power conversion efficiency.     

Artificially induced ferroelectric-like behavior in an antiferroelectric sandwich structure by interface engineering

Interface engineering is essential for achieving fascinating interfacial functionalities in a single all-oxide-interface-based device. In the present work, a sandwich structure (Pb_0.94La_0.06(Zr_0.95Ti_0.05)O₃ (PLZT)/HfO₂/ Pb_0.94La_0.06(Zr_0.95Ti_0.05)O₃) was fabricated via a chemical solution approach. A distinct “ferroelectricity-like” behavior with high P_max (～ 80 μC/cm²) and P_r (～ 36 μC/cm²) is demonstrated. The dielectric HfO₂ thin layer presents a tetragonal symmetry structure, which stabilizes a slight distorted structure of the upper PLZT layer (PLZT(T)) with a= 4.19(9) Å, b= 4.10(6) Å, β ～ 91.04?. In PLZT(T), the ferroelectric (FE) phase is identified as the matrix embedded with a small amount of AFE nanodomains, while the bottom PLZT layer (PLZT(B)) exhibits typical AFE incommensurately modulated structures. The near-interface structures in both PLZT layers are characterized by ferroelectric polarizations with head-to-tail configuration across the heterointerface. Such discontinuous, downward polarizations support the accumulation of oxygen vacancies at the heterointerface that facilitate the local polarization enhancement. It is the combination effect of stable ferroelectric polarization in the PLZT(T) layer, interfacial oxygen vacancies and large surface to volume ratio that leads to the superior polarization performance of the antiferroelectric sandwich structure. It indicates that interface engineering is a feasible approach to manipulate the ferroic behavior.