Oxygen‐Vacancy‐Endurable Conductors with Enhanced Transparency Using Correlated 4d² SrMoO₃ Thin Films

Abstract

Degenerately doped wide-bandgap semiconductors, e.g., Sn-doped In 2 O 3 , are the most conventional transparent conductors (TCs), but degradation of the TC performance by a doping bottleneck or instability due to oxygen vacancies is encountered. Recently, nondoped correlated metals have attracted great attention as a new strategy for developing next-generation TCs. To date, most studies of this brand-new type of TC have been biased toward 3d 1 vanadates. Here, compared with 3d 1 SrVO 3 , it is found that the 4d 2 SrMoO 3 thin films show promising TC properties: higher ultraviolet-visible transmittance of 80% and extremely low resistivity of 100 µΩ cm at room temperature. This enhancement in the SrMoO 3 is ascribed to a p-4d transition occurring at higher photon energy and a higher number of electrons in the outermost 4d orbitals, respectively. In addition, the TC properties of the correlated SrMoO 3 are resistive to oxygen vacancies. Using spectroscopic ellipsometry, it is found that this robustness is attributed to the lack of formation of defect states near the Fermi level, which is different from the observation in conventional TCs. Taken together, the correlated 4d 2 SrMoO 3 is appealing for next-generation oxygen-vacancy-endurable conductors with enhanced transparency.

Modifying Metastable Sr1–xBO3−δ (B = Nb, Ta, and Mo) Perovskites for Electrode Materials

“…Thus, when these defect states are fully suppressed, the two electrons per B 4+ ion that Mo possesses can contribute to significantly increasing its free carrier density. 66 However, in the case of SNO and STaO, the deep defect states are more difficult to fully suppress, resulting in the observed difference between the experimental and calculated ρ values. This behavior is consistent with other SNO calculations that reported inhibited electronic transport due to the presence of bulk defect states.…”

“…As displayed in Table 1 , the calculated ρ at the Fermi level is consistent with reported values. 36 , 65 , 66 Then, to mirror the measured SBO stoichiometries ( Tables S3 and S5 ), the following models were utilized: (i) for SMO, no Sr (V Sr ) and O (V O ) vacancies were incorporated into the corresponding defect-free model, (ii) for SNO, 2 V Sr and 2 V O vacancies were introduced into the corresponding defect-free model, and (iii) for STaO, 10 Na atoms (7 A-site, 3 B-site) and 5 V O were introduced into the corresponding defect-free model. The calculated band structures and density of states (DOS) for defective SBO NPs show that the Fermi level sits in the respective bands ( Figure S12 a–c, dashed red line), revealing that the observed electronic conductivity of these metastable crystals is a result of n-type (SNO and SMO) and p-type (STaO) behavior.…”

“…For SNO and SMO, the n-type conductivity arises from the partially occupied t 2g bands of the metal d orbitals. 21 , 66 In the case of STaO, it is believed that the partial substitution of Na into the Sr/Ta-sites of STaO significantly dopes hole carriers into the top of the valence band, resulting in the p-type conductivity. 67 From the above calculations, the electronic structure of metastable SBO perovskites is determined to be conducive to n- or p-type transport, depending on the nature of the B-site ion, making them robust conductors.…”

Synthesis of CaWO4:Ln3+ nanocomposites with high transparency via ligand‐assisted re‐precipitation method

“…Since absorption loss is not a key factor in the optical transparency of our nanocomposites (Figure 6B,C). In this case, where scattering losses dominate, the transparency loss (T) of the nanocomposites as a outcome of light scattering by randomly dispersed NCs with radius (r) and volume proportion of inorganic particles (ϕ p ) can be elaborated by the Rayleigh scattering equation: 17,[31][32][33]…”

Giant Tuning of Electronic and Thermoelectric Properties by Epitaxial Strain in p-Type Sr-Doped LaCrO3 Transparent Thin Films

“…These last few years, advanced n-type TCO have been intensively investigated, e.g. high-mobility stannates such as Ladoped BaSnO3, the electrical conductivity and thermoelectric properties of which can be tuned by aliovalent cationic substitution 14,15,16,17,18 , vanadates such as SrVO3 4,19,20 , and more recently molybdates such as SrMoO3 21,22 . In contrast, effective p-type TCO or transparent TEO are still to be found, which is a crucial issue for the continued development of oxide-based thermoelectric and optoelectronic devices.…”