Non-Invasive Modulation of Carrier Injection Efficiency via Electronic Phase Separation at Organic/Inorganic Interfaces

Abstract

Functional interfaces between magnetic oxides and organic semiconductors have led to a wealth of spin-dependent phenomena, enriching the fundamental understanding of spintronics and offering new routes for next-generation spintronic device engineering. However, modulation of carrier injection at such interfaces, particularly through non-invasive methods, has yet to be thoroughly investigated. This limitation hinders precise control over interfacial charge injection and restricts overall device efficiency. In this work, we construct an LPCMO/P3HT-based organic magnetoresistive diode and demonstrate highly efficient rectification of interfacial carrier transport by exploiting the electronic phase separation (EPS) in the magnetic electrode LPCMO. By tuning the internal EPS of LPCMO, we achieve distinct resistance switching states in the device. Notably, the observed change in device resistance exceeds that of the LPCMO electrode by a factor of 60, revealing a pronounced amplification effect at the interface. This giant modulation originates from the EPS-induced Fermi level shift in LPCMO, which reduces the interfacial energy barrier and significantly enhances carrier injection efficiency across the oxide/organic semiconductor interface. Our findings present a new strategy for precise and in-situ control of carrier injection processes, which may further advance both the scientific and technological frontiers of organic spintronics.