Role of Ionic Functional Groups on Ion Transport at Perovskite Interfaces. Issue 21 (7th August 2017)

• Record Type: Journal Article
• Authors: Liu, Yao; Renna, Lawrence A.; Thompson, Hilary B.; Page, Zachariah A.; Emrick, Todd; Barnes, Michael D.; Bag, Monojit; Venkataraman, D.; Russell, Thomas P.
• Is Part Of: Advanced energy materials. Volume 7:Issue 21(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-08-07
• Subjects: electrochemical impedance spectroscopy -- interface engineering -- interfacial ion adsorption -- interfacial ion transport -- perovskites; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.201701235
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Hybrid organic/inorganic perovskite solar cells are invigorating the photovoltaic community due to their remarkable properties and efficiency. However, many perovskite solar cells show an undesirable current–voltage ( I – V ) hysteresis in their forward and reverse voltage scans, working to the detriment of device characterization and performance. This hysteresis likely arises from slow ion migration in the bulk perovskite active layer to interfaces which may induce charge trapping. It is shown that interfacial chemistry between the perovskite and charge transport layer plays a critical role in ion transport and I – V hysteresis in perovskite‐based devices. Specifically, phenylene vinylene polymers containing cationic, zwitterionic, or anionic pendent groups are utilized to fabricate charge transport layers with specific interfacial ionic functionalities. The interfacial‐adsorbing boundary induced by the zwitterionic polymer in contact with the perovskite increases the local ion concentration, which is responsible for the observed I – V hysteresis. Moreover, the ion adsorbing properties of this interface are exploited for perovskite‐based memristors. This fundamental study of I – V hysteresis in perovskite‐based devices introduces a new mechanism for inducing memristor behavior by interfacial ion adsorption. Abstract : Ion migration at perovskite interfaces is investigated by varying the interface with cationic, anionic, and zwitterionic functionalities. The zwitterionic polymer interlayer generates an adsorbing boundary at the interface, increasing the local ion concentration, causing current–voltage ( I – V ) hysteresis in perovskite‐based devices. This fundamental study of perovskite I – V hysteresis introduces a new mechanism for device memristor behavior by interfacial ion adsorption.