Role of Ionic Functional Groups on Ion Transport at Perovskite Interfaces

Title

Role of Ionic Functional Groups on Ion Transport at Perovskite Interfaces

Subject

electrochemical impedance spectroscopy; interface engineering; interfacial ion adsorption; interfacial ion transport; perovskites; memristors

Description

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 (IV) 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 IV 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 IVhysteresis. Moreover, the ion adsorbing properties of this interface are exploited for perovskite-based memristors. This fundamental study of IV hysteresis in perovskite-based devices introduces a new mechanism for inducing memristor behavior by interfacial ion adsorption.

Source

Adv. Energy Mater. 2017, Article Nol: 1701235 [Link]

Publisher

Wiley

Date

2017

Contributor

Yao Liu, Lawrence A. Renna, Hilary B. Thompson, Zachariah A. Page, Todd Emrick, Michael D. Barnes, Monojit Bag, D. Venkataraman, Thomas P. Russell

Type

Article

Identifier

DOI:10.1002/aenm.201701235

Collection