Giant Electric Bias‐Induced Tunability of Photoluminescence and Photoresistance in Hybrid Perovskite Films on Ferroelectric Substrates

Abstract

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adom.201901092. Electric Bias-Induced ModulationHybrid perovskites (HPs), particularly methylammonium lead iodide (CH 3 NH 3 PbI 3 , hereafter MAPbI 3 ), have attracted enormous attention owing to their outstanding optoelectronic properties, such as tunable bandgap in the visible range, [1,2] long diffusion length, [3,4] superb optical absorption, [5] small exciton binding energy, [6] high ambipolar charge mobility, [7,8] and even ferroelectric polarization. [9] The solution-processed perovskite solar cells exhibit photovoltaic power conversion efficiency over 23%. [10][11][12][13] In addition to photovoltaic applications, HPs have also been exploited for light-emitting diodes, [14,15] lasing

Single‐Crystal Hybrid Perovskite Platelets on Graphene: A Mixed‐Dimensional Van Der Waals Heterostructure with Strong Interface Coupling

“…Metal‐halide perovskites have received intense research efforts owing to their extraordinary optical and electrical properties 18–22. Besides solution‐processed polycrystal films, bulk crystals, and nanocrystals, large‐scale ultrathin perovskites via vapor‐phase growth have attracted intensive research efforts 23–28.…”

Manipulation of perovskite film by bias‐induced reversible lattice deformation toward tunable photoelectric performances

“…[25] Also, the lattice change is around 0.01% under an applied electric field for only 0.06 V µm -1 , so does the reported electrostrictive response. [26] It is reported that the strain plays an indispensable role in influencing the electronic band structure of perovskites and the lattice deformation can give rise to the modulation of photoresistance for MAPbI 3 film. [26,29] Thus, we propose that the electrostriction causes the lattice deformation which can affect the photoresponse behavior of perovskite film.…”

“…To be noted, a V-shaped behavior corresponds to the incoherence of ΔR/R light on bias polarity, as shown in Figure 3B, which also agrees with the strain change of MAPbI 3 film under different bias. Importantly, it further indicates the dominant role of the lattice deformation in the photoresistance modulation, [26] which is subjected to further analysis. Furthermore, the bias-dependent R light of MAPbI 3 film is also measured under different irradiation powers in Fig- ure 3C.…”

“…[31][32][33][34] The observed contraction of crystals along the in-plane direction and the expansion in the out-of-plane direction indicate that the structure of MAPbI 3 becomes more tetragonal under the influence of bias, which would accompany by the decrease of carrier recombination and be manifested by the increase of free carrier. [26] Thus, the photoresistance and photoresponse are tuned.…”

“…Experimentally, the electromechanical properties are consecutively discovered in MAPbI 3 , such as electrostrictive and electroelastic properties, [24,25] which can give rise to the morphological or crystal-structural responses of perovskite under a certain external electric field. What is more, in one pioneering report, [26] we also modulated the luminescence and phototransport of MAPbI 3 films that grown on the piezoelectric platform via ferroelectric and piezoelectric effects, which leads us to ponder on the role of the lattice deformation on the material's unusual photophysical properties.…”