Implementation of data-cube pump-probe KPFM on organic solar cells

Benjamin Grévin; Olivier Bardagot; Renaud Demadrille

doi:10.3762/bjnano.11.24

Implementation of data-cube pump-probe KPFM on organic solar cells

Beilstein J Nanotechnol. 2020 Feb 12:11:323-337. doi: 10.3762/bjnano.11.24. eCollection 2020.

Authors

Benjamin Grévin¹, Olivier Bardagot¹, Renaud Demadrille¹

Affiliation

¹ Univ. Grenoble Alpes, CNRS, CEA, IRIG-SyMMES, 38000 Grenoble, France.

Abstract

An implementation of pump-probe Kelvin probe force microscopy (pp-KPFM) is reported that enables recording the time-resolved surface potential in single-point mode or over a 2D grid. The spectroscopic data are acquired in open z-loop configuration, which simplifies the pp-KPFM operation. The validity of the implementation is probed by measurements using electrical pumping. The dynamical photoresponse of a bulk heterojunction solar cell based on PTB7 and PC₇₁BM is subsequently investigated by recording point-spectroscopy curves as a function of the optical power at the cathode and by mapping 2D time-resolved images of the surface photovoltage of the bare organic active layer.

Keywords: Kelvin probe force microscopy (KPFM); bulk heterojunctions; organic photovoltaics; photocarrier dynamics; pump–probe configuration; time-resolved measurements.