Search

Perovskite based photovoltaic (PV) cells are unique in combining low open‐circuit voltage losses with a broad bandgap tunability. This makes them an ideal PV cell to recycle photons back into electrical power in a variety of illumination systems or light emitting devices. Here, advantage of these features is taken and wide bandgap (WBG) perovskite PV cells are incorporated in devices suitable for display illumination and demonstrate a high yield in stray light recycling back into electricity with up to a 37.5% power conversion efficiency. The specific device considered is a modified half‐cylinder photonic plate designed to emit diffused broadband polarized light using a nonabsorbing reflective polarizer based on a random dielectric layer distribution. It is experimentally demonstrated that light recycling using appropriately tuned WBG perovskite PV cells becomes very efficient when implemented in systems where the light is emitted from narrowband sources, even if the emission spans a broad wavelength range. [ABSTRACT FROM AUTHOR]

The phenomena related to charge trapping are among the most relevant open issues that affect the long-term stability of perovskite-based devices. According to this, the objective of this paper is to report experimental results in which a charge control strategy is used for the first time in a solar cell structure that has a high trap density perovskite absorber. This device has also noticeable J-V hysteresis, produced by non-capacitive effects. The control strategy proposed, based on sigma-delta modulation, applies to the device an appropriate sequence of voltage waveforms determined after periodical current measurements made at a constant voltage. The experimental results obtained and the fittings made with a phenomenological model indicate that this approach allows controlling several charge-related effects. As a consequence, the J-V characteristic of the device is successfully shifted and stabilized to predetermined positions. [ABSTRACT FROM AUTHOR]