Ferroelectric domain wall (DW) conduction, confirmed in recent experiments, has attracted intense attention due to its promising applications in optoelectronic devices. Herein, we provide theoretical evidence of electric conduction in Pb_0.8Ca_0.2TiO₃ (PCT) DWs. The separation of charge accumulation in DWs, corresponding to the electronic conduction-band minimum (CBM) and valence-band maximum (VBM), weakens the tendency for the electron-hole recombination, thereby providing more efficient channels for charge transfer. We fabricate PCT-based functional photovoltaic devices with polarization tunable charge transfer to exploit the combined conduction and ferroelectric properties of the DW. The photovoltaic performance of the devices can be regulated by the alternation of ferroelectric domains in PCT, caused by variation of the external poling. Our work broadens the applicability of DW conduction and may inspire the future design of high-performance materials in photovoltaic devices.

最近在实验中证实的铁电畴壁（DW）传导由于在光电器件中的应用前景广阔而引起了人们的极大关注。在此，我们提供了Pb _0.8 Ca _0.2 TiO _3中导电的理论证据（PCT）DW。对应于电子导带最小值（CBM）和价带最大值（VBM）的DW中电荷积累的分离，减弱了电子-空穴复合的趋势，从而为电荷转移提供了更有效的通道。我们制造具有极化可调电荷转移的基于PCT的功能性光伏器件，以利用DW的组合导电和铁电特性。可以通过由外部极化的变化引起的PCT中铁电畴的交替来调节设备的光伏性能。我们的工作拓宽了DW传导的适用范围，并可能激发光伏器件中高性能材料的未来设计。