Metal Halide Perovskite Dynamics Driven by Water and Light

Hybrid organic-inorganic perovskites present ideal properties for light-emitting diodes and photovoltaics, but are limited by their stability under multiple operating conditions [1]. We first elucidate the impact of relative humidity (rH) cycling on the luminescence properties of four Cs_xFA_1-xPb(I_yBr_1-y) perovskites using environmentally-controlled in situ micro-photoluminscence (PL) and discover PL hysteresis for all compositions but the 17%-Cs/38%-Br [2]. Next, we shift focus to light, and quantify the wavelength-dependent voltage dynamics in three perovskite compositions: (i) CH₃NH₃PbBr₃, (ii) (MA,FA,Cs)Pb(I,Br)₃, and (iii) CH₃NH₃PbI₃ across a dark-light-dark illumination cycle using heterodyne Kelvin Probe voltage measurements [3]. We conclude with a discussion of the potential for machine learning to identify and control the impact of all environmental parameters [1].

[1] J. M. Howard, et al., Joule, Accepted (2018) - Invited Perspective.

[2] J. M. Howard, et al., Journal of Physical Chemistry Letters, 9, 3463 (2018).

[3] E. M. Tennyson*, J. M. Howard*, et al., to be submitted (2018).