Quadrupling the depairing current density in the iron-based superconductor SmFeAsO1-xHx.

Iron-based 1111-type superconductors display high critical temperatures and relatively high critical current densities Jc. The typical approach to increasing Jc is to introduce defects to control dissipative vortex motion. However, when optimized, this approach is theoretically predicted to be limited to achieving a maximum Jc of only ∼30% of the depairing current density Jd, which depends on the coherence length and the penetration depth. Here we dramatically boost Jc in SmFeAsO1-xHx films using a thermodynamic approach aimed at increasing Jd and incorporating vortex pinning centres. Specifically, we reduce the penetration depth, coherence length and critical field anisotropy by increasing the carrier density through high electron doping using H substitution. Remarkably, the quadrupled Jd reaches 415 MA cm-2, a value comparable to cuprates. Finally, by introducing defects using proton irradiation, we obtain high Jc values in fields up to 25 T. We apply this method to other iron-based superconductors and achieve a similar enhancement of current densities.

Inverse-Perovskite Ba3 BO (B = Si and Ge) as a High Performance Environmentally Benign Thermoelectric Material with Low Lattice Thermal Conductivity.

High energy-conversion efficiency (ZT) of thermoelectric materials has been achieved in heavy metal chalcogenides, but the use of toxic Pb or Te is an obstacle for wide applications of thermoelectricity. Here, high ZT is demonstrated in toxic-element free Ba3 BO (B = Si and Ge) with inverse-perovskite structure. The negatively charged B ion contributes to hole transport with long carrier life time, and their highly dispersive bands with multiple valley degeneracy realize both high p-type electronic conductivity and high Seebeck coefficient, resulting in high power factor (PF). In addition, extremely low lattice thermal conductivities (κlat ) 1.0-0.4 W m-1  K-1 at T = 300-600 K are observed in Ba3 BO. Highly distorted O-Ba6 octahedral framework with weak ionic bonds between Ba with large mass and O provides low phonon velocities and strong phonon scattering in Ba3 BO. As a consequence of high PF and low κlat , Ba3 SiO (Ba3 GeO) exhibits rather high ZT = 0.16-0.84 (0.35-0.65) at T = 300-623 K (300-523 K). Finally, based on first-principles carrier and phonon transport calculations, maximum ZT is predicted to be 2.14 for Ba3 SiO and 1.21 for Ba3 GeO at T = 600 K by optimizing hole concentration. Present results propose that inverse-perovskites would be a new platform of environmentally-benign high-ZT thermoelectric materials.

Characteristic Resistive Switching of Rare-Earth Oxyhydrides by Hydride Ion Insertion and Extraction.

Resistive switching induced by ion migration is promising for applications such as random-access memory (ReRAM) and neuromorphic transistors. Hydride ions (H-) are an interesting candidate as the migration ion for resistive switching devices because they have fast diffusion in several compounds at room temperature and doping/dedoping can be used effectively to achieve significant changes in the electronic conductivity. Here, we report reversible resistive switching characteristics in rare-earth oxyhydrides (REHxO(3-x)/2) induced by field insertion/extraction of H-. The current-voltage measurements revealed that the resistive switching response, hysteresis, and switching voltage vary greatly with the H-/O2- ratio in the films. We fabricated a ReRAM device using Ti/YH1.3O0.85/MoOx structure and confirmed the bipolar-type operation with the resistance switching ratio of 1 order of magnitude over 1000 cycles. The composition gradient of H-/O2- in YHxO(3-x)/2 films, in addition to the hydrogen-absorbing ability of the top electrode, is essential for effective device operation. Our findings show that hydride-conducting solid-state electrolytes are suitable for resistive switching device development.

Design, Synthesis, and Optoelectronic Properties of the High-Purity Phase in Layered AETMN2 (AE = Sr, Ba; TM = Ti, Zr, Hf) Semiconductors.

We report the synthesis and optoelectronic properties of high phase-purity (>94 mol %) bulk polycrystals of KCoO2-type layered nitrides AETMN2 (AE = Sr, Ba; and TM = Ti, Zr, Hf), which are expected to exhibit unique electron transport properties originating from their natural two-dimensional (2D) electronic structure, but high-purity intrinsic samples have yet been reported. The bulks were synthesized using a solid-state reaction between AENH and TMN precursors with NaN3 to achieve high N chemical potential during the reaction. The AETMN2 bulks are n-type semiconductors with optical band gaps of 1.63 eV for SrTiN2, 1.97 eV for BaZrN2, and 2.17 eV for BaHfN2. SrTiN2 and BaZrN2 bulks show degenerated electron conduction due to the natural high-density electron doping and paramagnetic behavior in all of the temperature ranges examined, while such unintentional carrier generation is largely suppressed in BaHfN2, which exhibits nondegenerated electron conduction. The BaHfN2 sample also exhibits weak ferromagnetic behavior at temperatures lower than 35 K. Density functional theory calculations suggest that the high-density electron carriers in SrTiN2 come from oxygen impurity substitution at the N site (ON) acting as a shallow donor even if the high-N chemical potential synthesis conditions are employed. On the other hand, the formation energy of ON becomes larger in BaHfN2 because of the stronger TM-N chemical bonds. Present results demonstrate that the easiness of impurity incorporation is designed by density functional calculations to produce a more intrinsic semiconductor in wider chemical conditions, opening a way to cultivating novel functional materials that are sensitive to atmospheric impurities and defects.

High-Mobility Metastable Rock-Salt Type (Sn,Ca)Se Thin Film Stabilized by Direct Epitaxial Growth on a YSZ (111) Single-Crystal Substrate.

Metastable cubic (Sn1-xPbx)Se with x ≥ 0.5 is expected to be a high mobility semiconductor due to its Dirac-like electronic state, but it has an excessively high carrier concentration of ∼1019 cm-3 and is not suitable for semiconductor device applications such as thin film transistors and solar cells. Further, thin films of (Sn1-xPbx)Se require a complicated synthesis process because of the high vapor pressure of Pb. We herein report the direct growth of metastable cubic (Sn1-xCax)Se films alloyed with CaSe, which has a wider bandgap and lower vapor pressure than PbSe. The cubic (Sn1-xCax)Se epitaxial films with x = 0.4-0.8 are stabilized on YSZ (111) single crystalline substrates by pulsed laser deposition. (Sn1-xCax)Se has a direct-transition-type bandgap, and the bandgap energy can be varied from 1.4 eV (x = 0.4) to 2.0 eV (x = 0.8) by changing x. These films with x = 0.4-0.6 show p-type conduction with low hole carrier concentrations of ∼1017 cm-3. Hall mobility analysis suggests that the hole transport would be dominated by 180° rotational domain structures, which is specific to (111) oriented epitaxial films. However, it, in turn, clarifies that the in-grain carrier mobility in the (Sn0.6Ca0.4)Se film is as high as 322 cm2/(Vs), which is much higher than those in thermodynamically stable layered SnSe and other Sn-based layered semiconductor films at room temperature. Therefore, the present results prove the potential of high mobility (Sn1-xCax)Se films for semiconductor device applications via a simple thin-film deposition process.

Degenerated Hole Doping and Ultra-Low Lattice Thermal Conductivity in Polycrystalline SnSe by Nonequilibrium Isovalent Te Substitution.

Tin mono-selenide (SnSe) exhibits the world record of thermoelectric conversion efficiency ZT in the single crystal form, but the performance of polycrystalline SnSe is restricted by low electronic conductivity (σ) and high thermal conductivity (κ), compared to those of the single crystal. Here an effective strategy to achieve high σ and low κ simultaneously is reported on p-type polycrystalline SnSe with isovalent Te ion substitution. The nonequilibrium Sn(Se1- x Tex ) solid solution bulks with x up to 0.4 are synthesized by the two-step process composed of high-temperature solid-state reaction and rapid thermal quenching. The Te ion substitution in SnSe realizes high σ due to the 103 -times increase in hole carrier concentration and effectively reduced lattice κ less than one-third at room temperature. The large-size Te ion in Sn(Se1- x Tex ) forms weak SnTe bonds, leading to the high-density formation of hole-donating Sn vacancies and the reduced phonon frequency and enhanced phonon scattering. This result-doping of large-size ions beyond the equilibrium limit-proposes a new idea for carrier doping and controlling thermal properties to enhance the ZT of polycrystalline SnSe.

Breaking of Thermopower-Conductivity Trade-Off in LaTiO3 Film around Mott Insulator to Metal Transition.

Introducing artificial strain in epitaxial thin films is an effective strategy to alter electronic structures of transition metal oxides (TMOs) and to induce novel phenomena and functionalities not realized in bulk crystals. This study reports a breaking of the conventional trade-off relation in thermopower (S)-conductivity (σ) and demonstrates a 2 orders of magnitude enhancement of power factor (PF) in compressively strained LaTiO3 (LTO) films. By varying substrates and reducing film thickness down to 4 nm, the out-of-plane to the in-plane lattice parameter ratio is controlled from 0.992 (tensile strain) to 1.034 (compressive strain). This tuning induces the electronic structure change from a Mott insulator to a metal and leads to a 103 -fold increase in σ up to 2920 S cm-1 . Concomitantly, the sign of S inverts from positive to negative, and both σ and S increase and break the trade-off relation between them in the n-type region. As a result, the PF (=S2 σ) is significantly enhanced to 300 µW m- 1 K-2 , which is 102 times larger than that of bulk LTO. Present results propose epitaxial strain as a means to finely tune strongly correlated TMOs close to their Mott transition, and thus to harness the hidden large thermoelectric PF.

Large phonon drag thermopower boosted by massive electrons and phonon leaking in LaAlO3/LaNiO3/LaAlO3 heterostructure.

An unusually large thermopower (S) enhancement is induced by heterostructuring thin films of the strongly correlated electron oxide LaNiO3. The phonon-drag effect, which is not observed in bulk LaNiO3, enhances S for thin films compressively strained by LaAlO3 substrates. By a reduction in the layer thickness down to three unit cells and subsequent LaAlO3 surface termination, a 10 times S enhancement over the bulk value is observed due to large phonon drag S (Sg), and the Sg contribution to the total S occurs over a much wider temperature range up to 220 K. The Sg enhancement originates from the coupling of lattice vibration to the d electrons with large effective mass in the compressively strained ultrathin LaNiO3, and the electron-phonon interaction is largely enhanced by the phonon leakage from the LaAlO3 substrate and the capping layer. The transition-metal oxide heterostructures emerge as a new playground to manipulate electronic and phononic properties in the quest for high-performance thermoelectrics.

Reversible 3D-2D structural phase transition and giant electronic modulation in nonequilibrium alloy semiconductor, lead-tin-selenide.

Material properties depend largely on the dimensionality of the crystal structures and the associated electronic structures. If the crystal-structure dimensionality can be switched reversibly in the same material, then a drastic property change may be controllable. Here, we propose a design route for a direct three-dimensional (3D) to 2D structural phase transition, demonstrating an example in (Pb1-x Sn x )Se alloy system, where Pb2+ and Sn2+ have similar ns2 pseudo-closed shell configurations, but the former stabilizes the 3D rock-salt-type structure while the latter a 2D layered structure. However, this system has no direct phase boundary between these crystal structures under thermal equilibrium. We succeeded in inducing the direct 3D-2D structural phase transition in (Pb1-x Sn x )Se alloy epitaxial films by using a nonequilibrium growth technique. Reversible giant electronic property change was attained at x ~ 0.5 originating in the abrupt band structure switch from gapless Dirac-like state to semiconducting state.

Strain Engineering at Heterointerfaces: Application to an Iron Pnictide Superconductor, Cobalt-Doped BaFe2As2.

We propose a unique strategy to apply stronger strain at heterointerfaces than conventional epitaxial strain methods to extract hidden attractive physical/chemical properties in materials. This strategy involves precisely accounting for the epitaxial strain induced by lattice mismatch as well as the differences in the thermal expansion coefficients and compressibilities of epitaxial films and substrates. We selected optimally cobalt-doped BaFe2As2(Ba122:Co), an iron-based superconductor with a bulk critical temperature (Tc) of 22 K, as a model material and four types of single-crystal substrates. Ba122:Co was selected because its Tc is robust to hydrostatic pressure but sensitive to epitaxial strain (i.e., one of the anisotropic strains), and the selected substrates entirely cover the positive/negative lattice mismatches, thermal expansion coefficients, and compressibilities with respect to Ba122:Co. With strong anisotropic strain successfully induced by film growth, external hydrostatic pressurizing, and cooling processes, we observed unique carrier transport properties in Ba122:Co epitaxial films on CaF2 and BaF2 substrates including (i) upturn behavior in the temperature dependence of the longitudinal resistivity, (ii) negative magnetoresistance, (iii) large enhancement of anomalous Hall effects in the epitaxial films on CaF2, and (iv) enhancement of Tc to 27 K in the epitaxial films on BaF2. These results demonstrate the effectiveness of our strategy, and this approach can be further extended to other inorganic materials in thin-film form.

Coexistence of magnetism and superconductivity in thin films of the Fe-based superconductor Ba1-xLaxFe2As2.

Magnetization measurements have been performed to understand the role of the magnetic structure on the superconducting properties of epitaxial thin films of Ba1-x La x Fe2As2 (x = 0.08, 0.13, and 0.18) deposited on single crystal (001)-oriented MgO substrates by pulsed laser deposition. All samples exhibit a reentrant-spinglass like behavior at normal state. At lower temperatures, we observe the same magnetic state coexisting with superconductivity and it is also observed a prominent non-linear giant diamagnetism in an intermediate temperature range just above the superconducting phase transition temperature. Furthermore, no significant change in the magnetic domain structure was detected by the onset of superconductivity. Based on their magnetic states, we claim that each domain (as a disconnected superconducting island) has its own bulk superconducting properties. Finally, we discussed the dual character played by the La atoms in the superconducting properties. That duality character has been also confirmed by analyzing resistivity data.

Tunable Light Emission through the Range 1.8-3.2 eV and p-Type Conductivity at Room Temperature for Nitride Semiconductors, Ca(Mg1-xZnx)2N2 (x = 0-1).

The ternary nitride CaZn2N2, composed only of earth-abundant elements, is a novel semiconductor with a band gap of ∼1.8 eV. First-principles calculations predict that continuous Mg substitution at the Zn site will change the optical band gap in a wide range from ∼3.3-1.9 eV for Ca(Mg1-xZnx)2N2 (x = 0-1). In this study, we demonstrate that a solid-state reaction at ambient pressure and a high-pressure synthesis at 5 GPa produce x = 0 and 0.12 and 0.12 < x ≤ 1 polycrystalline samples, respectively. It is experimentally confirmed that the optical band gap can be continuously tuned from ∼3.2 to ∼1.8 eV, a range very close to that predicted by theory. Band to band photoluminescence is observed at room temperature in the ultraviolet-red region depending on x. A 2% Na doping at the Ca site of Ca(Mg1-xZnx)2N2 converts its highly resistive state to a p-type conducting state. Particularly, the x = 0.50 sample exhibits intense green emission with a peak at 2.45 eV (506 nm) without any other emission from deep-level defects. These features meet the demands of III-V group nitride and arsenide/phosphide light-emitting semiconductors.

Material Design of Green-Light-Emitting Semiconductors: Perovskite-Type Sulfide SrHfS3.

A current issue facing light-emitting devices is a missing suitable material for green emission. To overcome this, we explore semiconductors possessing (i) a deep conduction band minimum (CBM) and a shallow valence band maximum (VBM), (ii) good controllability of electronic conductivity and carrier polarity, and (iii) a directly allowed band gap corresponding to green emission. We focus on early transition metal ( eTM)-based perovskites. The eTM cation's high and stable valence state makes its carrier controllability easy, and the eTM's nonbonding d orbital and the anion's p orbital, which constitute the deep CBM and shallow VBM, are favorable to n- and p-type doping, respectively. To obtain a direct band gap, we applied a scheme that folds the bands constituting the VBM at the zone boundary to the zone center where the CBM appears. Orthorhombic SrHfS3 was chosen as the candidate. The electrical conductivity was tuned from 6 × 10-7 to 7 × 10-1 S·cm-1 with lanthanum (La) doping and to 2 × 10-4 S·cm-1 with phosphorus (P) doping. Simultaneously, the major carrier polarity was controlled to n type by La doping and to p type by P doping. Both the undoped and doped SrHfS3 exhibited intense green photoluminescence (PL) at 2.37 eV. From the PL blue shift and short lifetime, we attributed the emission to a band-to-band transition and/or exciton. These results demonstrate that SrHfS3 is a promising green-light-emitting semiconductor.

Superconducting transition temperatures in the electronic and magnetic phase diagrams of Sr2VFeAsO3-δ , a superconductor.

We elucidate the magnetic phases and superconducting (SC) transition temperatures (T c) in Sr2VFeAsO3-δ (21113V), an iron-based superconductor with a thick-blocking layer fabricated from a perovskite-related transition metal oxide. At low temperatures (T < 37.1 K), 21113V exhibited a SC phase in the range 0.031 ⩽ δ ⩽ 0.145 and an antiferromagnetic (AFM) iron sublattice in the range 0.267 ⩽ δ ⩽ 0.664. Mixed-valent vanadium exhibited a dominant AFM phase in 0.031 ⩽ δ ⩽ 0.088, and a partial ferrimagnetic (Ferri.) phase in the range 0.124 ⩽ δ ⩽ 0.664. The Ferri. phase was the most dominant at a δ value of 0.267, showing an AFM phase of Fe at T < 20 K. Increasing the spontaneous magnetic moments reduced the magnetic shielding volume fraction due to the SC phase. This result was attributed to the magnetic phase of vanadium, which dominates the superconductivity of Fe in 21113V. The T c-δ curve showed two maxima. The smaller and larger of T c maxima occurred at δ = 0.073 and δ = 0.145, respectively; the latter resides on the phase boundary between AFM and the partial Ferri. phases of vanadium. 21113V is a useful platform for verifing new mechanisms of T c enhancement in iron-based superconductors.

Multiple states and roles of hydrogen in p-type SnS semiconductors.

Hydrogen (H) plays critical roles in the electrical properties of semiconductor materials and devices. In this work, we report multiple states and roles of H in SnS by H plasma treatment and density functional theory (DFT) calculations. The as-deposited SnS films include impurity H at 2.3 × 1019 cm-3, four orders of magnitude larger than the hole density. The DFT calculations reveal that H exists in multiple states at the equilibrium mainly at the interstitial and the Sn-substitutional sites, which have formation enthalpies lower than those for the intrinsic defects. These H states work as donors and acceptors, respectively, and strongly pin the Fermi level in the p-type region. The native p-type conduction in the actual SnS semiconductors is caused mainly by the H-on-Sn (HSn) acceptors, rather than the previously reported Sn vacancies (VSn) for pure SnS. It is also confirmed that even stronger H doping with larger H chemical potentials cannot convert SnS to an n-type conductor because it reduces SnS to Sn metal.

Phase transition in CaFeAsH: bridging 1111 and 122 iron-based superconductors.

Iron-based superconductors can be categorized into two types of parent compounds by considering the nature of their temperature-induced phase transitions; namely, first order transitions for 122- and 11-type compounds and second-order transitions for 1111-type compounds. This work examines the structural and magnetic transitions (ST and MT) of CaFeAsH by specific heat, X-ray diffraction, neutron diffraction, and electrical resistivity measurements. Heat capacity measurements revealed a second-order phase transition that accompanies an apparent single peak at 96 K. However, a clear ST from the tetragonal to orthorhombic phase and an MT from the paramagnetic to the antiferromagnetic phase were detected. The structural (Ts) and Néel temperatures (TN) were respectively determined to be 95(2) and 96 K by X-ray and neutron diffraction and resistivity measurements. This small temperature difference, Ts-TN, was attributed to strong magnetic coupling in the inter-layer direction owing to CaFeAsH having the shortest lattice constant c among parent 1111-type iron arsenides. Considering that a first-order transition takes place in 11- and 122-type compounds with a short inter-layer distance, we conclude that the nature of the ST and MT in CaFeAsH is intermediate in character, between the second-order transition for 1111-type compounds and the first-order transition for other 11- and 122-type compounds.

Exploration of Stable Strontium Phosphide-Based Electrides: Theoretical Structure Prediction and Experimental Validation.

Inspired by the successful synthesis of alkaline-earth-metals-based electrides [Ca24Al28O64]4+(e-)4 (C12A7:e-) and [Ca2N]+:e- and high-throughput database screening results, we explore the potential for new electrides to emerge in the Sr-P system through a research approach combining ab initio evolutionary structure searches and experimental validation. Through employing an extensive evolutionary structure search and first-principles calculations, we first predict the new structures of a series of strontium phosphides: Sr5P3, Sr8P5, Sr3P2 and Sr4P3. Of these structures, we identify Sr5P3 and Sr8P5 as being potential electrides with quasi-one-dimensional (1D) and zero-dimensional (0D) character, respectively. Following these theoretical results, we present the successful synthesis of the new compound Sr5P3 and the experimental confirmation of its structure. Although density functional calculations with the generalized gradient approximation predict Sr5P3 to be a metal, electrical conductivity measurement reveal semiconducting properties characterized by a distinct band gap, which indicates that the newly synthesized Sr5P3 is an ideal one-dimensional electride with the half-filled band by unpaired electrons. In addition to presenting the novel electride Sr5P3, we discuss the implications of its semiconducting nature for 1D electrides in general and propose a mechanism for the formation of electrides with an orbital level diagram based on first-principles calculations.

An Exceptionally Narrow Band-Gap (∼4 eV) Silicate Predicted in the Cubic Perovskite Structure: BaSiO3.

The electronic structures of 35 A2+B4+O3 ternary cubic perovskite oxides, including their hypothetical chemical compositions, were calculated by a hybrid functional method with the expectation that peculiar electronic structures and unique carrier transport properties suitable for semiconductor applications would be hidden in high-symmetry cubic perovskite oxides. We found unique electronic structures of Si-based oxides (A = Mg, Ca, Sr, and Ba, and B = Si). In particular, the unreported cubic BaSiO3 has a very narrow band gap (4.1 eV) compared with conventional nontransition-metal silicates (e.g., ∼9 eV for SiO2 and the calculated value of 7.3 eV for orthorhombic BaSiO3) and a small electron effective mass (0.3m0, where m0 is the free electron rest mass). The narrow band gap is ascribed to the nonbonding state of Si 3s and the weakened Madelung potential. The existence of the predicted cubic perovskite structure of BaSiO3 was experimentally verified by applying a high pressure of 141 GPa. The present finding indicates that it could be possible to develop a new transparent oxide semiconductor of earth abundant silicates if the symmetry of its crystal structure is appropriately chosen. Cubic BaSiO3 is a candidate for high-performance oxide semiconductors if this phase can be stabilized at room temperature and ambient pressure.

Highly hydrogen-sensitive thermal desorption spectroscopy system for quantitative analysis of low hydrogen concentration (∼1 × 1016 atoms/cm3) in thin-film samples.

We developed a highly hydrogen-sensitive thermal desorption spectroscopy (HHS-TDS) system to detect and quantitatively analyze low hydrogen concentrations in thin films. The system was connected to an in situ sample-transfer chamber system, manipulators, and an rf magnetron sputtering thin-film deposition chamber under an ultra-high-vacuum (UHV) atmosphere of ∼10-8 Pa. The following key requirements were proposed in developing the HHS-TDS: (i) a low hydrogen residual partial pressure, (ii) a low hydrogen exhaust velocity, and (iii) minimization of hydrogen thermal desorption except from the bulk region of the thin films. To satisfy these requirements, appropriate materials and components were selected, and the system was constructed to extract the maximum performance from each component. Consequently, ∼2000 times higher sensitivity to hydrogen than that of a commercially available UHV-TDS system was achieved using H+-implanted Si samples. Quantitative analysis of an amorphous oxide semiconductor InGaZnO4 thin film (1 cm × 1 cm × 1 µm thickness, hydrogen concentration of 4.5 × 1017 atoms/cm3) was demonstrated using the HHS-TDS system. This concentration level cannot be detected using UHV-TDS or secondary ion mass spectroscopy (SIMS) systems. The hydrogen detection limit of the HHS-TDS system was estimated to be ∼1 × 1016 atoms/cm3, which implies ∼2 orders of magnitude higher sensitivity than that of SIMS and resonance nuclear reaction systems (∼1018 atoms/cm3).

High-field transport properties of a P-doped BaFe2As2 film on technical substrate.

High temperature (high-Tc) superconductors like cuprates have superior critical current properties in magnetic fields over other superconductors. However, superconducting wires for high-field-magnet applications are still dominated by low-Tc Nb3Sn due probably to cost and processing issues. The recent discovery of a second class of high-Tc materials, Fe-based superconductors, may provide another option for high-field-magnet wires. In particular, AEFe2As2 (AE: Alkali earth elements, AE-122) is one of the best candidates for high-field-magnet applications because of its high upper critical field, Hc2, moderate Hc2 anisotropy, and intermediate Tc. Here we report on in-field transport properties of P-doped BaFe2As2 (Ba-122) thin films grown on technical substrates by pulsed laser deposition. The P-doped Ba-122 coated conductor exceeds a transport Jc of 105 A/cm2 at 15 T for main crystallographic directions of the applied field, which is favourable for practical applications. Our P-doped Ba-122 coated conductors show a superior in-field Jc over MgB2 and NbTi, and a comparable level to Nb3Sn above 20 T. By analysing the E - J curves for determining Jc, a non-Ohmic linear differential signature is observed at low field due to flux flow along the grain boundaries. However, grain boundaries work as flux pinning centres as demonstrated by the pinning force analysis.