Ferroelectric diodes hold significant promise for potential applications in nonvolatile memories and logic devices. The nondestructive readout of binary information can be achieved by using a bipolar switching with two different conductances under two opposite polarizations in a ferroelectric diode, which exhibits ultrahigh density and ultrafast operating speed. However, the diode current is limited because most ferroelectrics have wide band gaps. Therefore, in modern micromemory circuits, obtaining a sufficient ferroresistive diode current to detect the status of memory stably is a major challenge. Herein, a high current-intensity resistive switching behavior in nanometer-thick BiFe_0.9Co_0.1O₃ films is reported. Epitaxial films were prepared on a (00l) Nb/SrTiO₃ single-crystal substrate via the chemical solution epitaxial deposition method. The conductance of the BiFeO₃ diode improved by up to 200 times that of the original. This improvement can be attributed to the bandgap decrease in ferroelectric film induced by Co doping, as confirmed by spectrophotometry and first-principles calculations. This device shows a stable bipolar resistive switching feature, a satisfactory switching ratio of ∼10³, good data retention, and antifatigue characteristics for up to 10⁷ cycles. The results are useful in exploring the potential applications of a ferroelectric diode in RRAM.

中文翻译：

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纳米厚度钴掺杂BiFeO ₃薄膜中用于存储应用的伪电阻二极管电流

铁电二极管在非易失性存储器和逻辑器件中的潜在应用前景广阔。可以通过在铁电二极管中使用具有两个不同电导的两个相反电导率的双极开关来实现二进制信息的无损读取，该铁电二极管具有超高密度和超快工作速度。但是，二极管电流受到限制，因为大多数铁电体都具有宽带隙。因此，在现代微存储器电路中，获得足够的铁磁二极管电流以稳定地检测存储器的状态是一个重大挑战。在此，报道了在纳米厚的BiFe _0.9 Co _0.1 O ₃膜中的高电流强度的电阻切换行为。在（00l）通过化学溶液外延沉积法制备Nb / SrTiO ₃单晶衬底。BiFeO ₃二极管的电导率提高了原来的200倍。如分光光度法和第一性原理计算所证实的，这种改善可归因于由Co掺杂引起的铁电薄膜带隙的减小。该器件具有稳定的双极性电阻开关功能，令人满意的开关比〜10 ³，良好的数据保持能力以及长达10 ⁷个周期的抗疲劳特性。该结果对于探索铁电二极管在RRAM中的潜在应用很有用。