Fig. 4: Proof-of-concept devices.
From: Solid-phase hetero epitaxial growth of α-phase formamidinium perovskite
a Device structure schematics and corresponding cross-sectional scanning electron microscopy (SEM) image of the solar cell device based on the FAPbI3 film with nano heteroepitaxy (NHE, with 3.33 mol% FPEA2PbI4). b Current density–voltage (J–V) and c external quantum efficiency (EQE) curves of solar cell devices based on a bare FAPbI3 film (control) and a FAPbI3 film with NHE. Inset of b shows the steady-state power conversion efficiencies (SSPCEs) measured at maximum power points. d Voltage–radiance curves of the light emitting diode (LED) devices, and e corresponding EQE curves of the LED devices based on the control and NHE films. Inset of d shows the electroluminescence spectra of the LED devices. Operational stability measurements of the f solar cell (normalized SSPCE) and g LED devices (normalized radiance) based on the control and NHE films.
