biostudies-literatureMaguire JRUK Research and InnovationEngineering and Physical Sciences Research Council10360-10366https://www.ebi.ac.uk/biostudies/studies/S-EPMC10683062biostudies-literatureUnknown23(22)We have used high-voltage Kelvin probe force microscopy to map the spatial distribution of electrical potential, dropped along curved current-carrying conducting domain walls, in x-cut single-crystal ferroelectric lithium niobate thin films. We find that <i>in-operando</i> potential profiles and extracted electric fields, associated with <i>p-n</i> junctions contained within the walls, can be fully rationalized through expected variations in wall resistivity alone. There is no need to invoke additional physics (carrier depletion zones and space-charge fields) normally associated with extrinsically doped semiconductor <i>p-n</i> junctions. Indeed, we argue that this should not even be expected, as inherent Fermi level differences between <i>p</i> and <i>n</i> regions, at the core of conventional <i>p-n</i> junction behavior, cannot occur in domain walls that are surrounded by a common matrix. This is important for domain-wall nanoelectronics, as such in-wall junctions will neither act as diodes nor facilitate transistors in the same way as extrinsic semiconducting systems do.Nano lettersFerroelectric Domain Wall p-n Junctions.PMC10683062EP/P02453X/1MR/T043172/1Suna AMaguire JRMcQuaid RGPGregg JMHolsgrove KMKumar AMcCluskey CJfalseFerroelectric Domain Wall p-n Junctions.We have used high-voltage Kelvin probe force microscopy to map the spatial distribution of electrical potential, dropped along curved current-carrying conducting domain walls, in x-cut single-crystal ferroelectric lithium niobate thin films. We find that <i>in-operando</i> potential profiles and extracted electric fields, associated with <i>p-n</i> junctions contained within the walls, can be fully rationalized through expected variations in wall resistivity alone. There is no need to invoke additional physics (carrier depletion zones and space-charge fields) normally associated with extrinsically doped semiconductor <i>p-n</i> junctions. Indeed, we argue that this should not even be expected, as inherent Fermi level differences between <i>p</i> and <i>n</i> regions, at the core of conventional <i>p-n</i> junction behavior, cannot occur in domain walls that are surrounded by a common matrix. This is important for domain-wall nanoelectronics, as such in-wall junctions will neither act as diodes nor facilitate transistors in the same way as extrinsic semiconducting systems do.2023-01-01T00:00:00Z2023 Nov2025-04-18T13:12:18.207Z2025-04-06T22:44:09.554ZS-EPMC106830623794738010.1021/acs.nanolett.3c02966