Work

Transformation of the Excited State and Photovoltaic Efficiency of CH3NH3PbI3 Perovskite upon Controlled Exposure to Humidified Air

Year: 2015

Type: article

Abstract: Humidity has been an important factor, in both negative and positive ways, in the development of perovskite solar cells and will prove critical in the push to commercialize this exciting new photovoltaic technology. The interaction between CH(3)NH(3)PbI(3) and H(2)O vapor is investigated by characterizing the ground-state and excited-state optical absorption properties and probing morphology and crystal structure. These undertakings reveal that H(2)O exposure does not simply cause CH(3)NH(3)PbI(3) to revert to PbI(2). It is shown that, in the dark, H(2)O is able to complex with the perovskite, forming a hydrate product similar to (CH(3)NH(3))(4)PbI(6)·2H(2)O. This causes a decrease in absorption across the visible region of the spectrum and a distinct change in the crystal structure of the material. Femtosecond transient absorption spectroscopic measurements show the effect that humidity has on the ultrafast excited state dynamics of CH(3)NH(3)PbI(3). More importantly, the deleterious effects of humidity on complete solar cells, specifically on photovoltaic efficiency and stability, are explored in the light of these spectroscopic understandings.

Source: Journal of the American Chemical Society

DOI: 10.1021/ja511132a

Authors: Jeffrey A. Christians, Pierre A. Miranda Herrera, Prashant V. Kamat

Institutions: University of Notre Dame, Tecnológico de Monterrey

Language: English

Topic: Perovskite Materials and Applications

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $4,500