Electric-Field-Induced Dynamic Electronic Junctions in Hybrid Organic–Inorganic Perovskites for Optoelectronic Applications

Abstract

Organic–inorganic metal halide perovskites have attracted great attention as optoelectronic materials because of their low cost, relative insensitivity to defects, and solution-processible properties. However, some of their properties, such as thermal instability, toxicity, and current–voltage hysteresis still remain elusive. Ion migration, which has been proven to be a thermal-activated process, is regarded as one of the major origins of the hysteresis and thus detrimental to the long-term stability of the optoelectronic devices. Nevertheless, by using the external electric field to pole the perovskite, ion migration would be possible to be utilized to create dynamic electronic junctions. In this paper, electric-field-induced dynamic electronic junctions have been manipulated for photodetection and energy harvesting through the ion migration under external electric field. Ion-migration-induced p–n or n–p junction has been successfully created via tuning the polarity of the external applied voltage, which is used for photodetection with a relatively fast response. By freezing out of the nonuniformly distributed ions after migration at low temperature, we demonstrate that the ion-migration-induced dynamic junctions can function as an energy harvesting device with an external quantum efficiency of 20%.

Dual‐Ion‐Diffusion Induced Degradation in Lead‐Free Cs2AgBiBr6 Double Perovskite Solar Cells

“…The new understandings of the ion-migration in the lead-free halide double perovskites can promote designing strategies for further materials and device stability improvement. Despite the adverse influence on the stability, it's noted that the ion-migration phenomenon in the metal halide perovskites is a "double-edged sword," which has been found to facilitate the fast response in photodetectors by forming dynamic electronic junctions [48,49] and also demonstrate important applications in resistance-switching memory devices [50][51][52] and artificial synapses. [53]…”

Revealing Electrical‐Poling‐Induced Polarization Potential in Hybrid Perovskite Photodetectors

“…The ions redistribution would induce an internal electric field inside the optoelectronic device. [ 39,40 ] Notably, it has been reported that the ion‐redistribution‐triggered p–i–n junction leads to the increased open‐circuit voltage and short‐circuit current of solar cells. [ 16,25 ] Here, either the internal electric field or the p–i–n junction does not contribute to the enhanced photocurrents of the MAPbBr 3 ‐film‐based photodetector in this work due to the following two reasons.…”

Ion Migration: A “Double‐Edged Sword” for Halide‐Perovskite‐Based Electronic Devices

“…Moreover, ion migration has found important application in perovskite resistance‐switching memory devices . Finally, by manipulating the ion migration progress under different electric field, dynamic electronic junctions are demonstrated and can be used as fast response photodetectors . Therefore, understanding and manipulating of the ion migration process in HOIP materials, which has been a formidable challenge, holds the key for developing “state of the art” perovskite devices.…”