Design Growth of MAPbI₃ Single Crystal with (220) Facets Exposed and Its Superior Optoelectronic Properties

Abstract

MAPbI is deemed as the most prominent member in hybrid perovskites family because of its extremely optoelectronic properties. However, some issues and puzzles are still in expectation of their answers, such as stabilities, hysteresis, ferroelectricity, and so on. To bridge the distinctions between MAPbI single crystal and thin films, large-size single crystals are demanded. On the contrary, crystal structure anisotropy-dependent optoelectronic properties is an inevitable topic. A series of large-size MAPbI single crystals with (220) facets exposed were successfully grown, using high concentration solutions and large-size seed crystals to match growth rates of (100) and (220) facets. The optoelectronic properties of photocurrents, responsivity, EQE, and detectivity clearly showed significant anisotropy of optoelectronic properties in MAPbI single crystal. According to ion migration theory, the anisotropy of optoelectronic properties was interpreted. We hope this result will be helpful to guide oriented growth MAPbI thin films.

Reduced ion migration and enhanced photoresponse in cuboid crystals of methylammonium lead iodide perovskite

“…CH3NH3PbI3 perovskite is generally grown into rhombic shape with facets oriented along the (112) and (200) planes. 19,21 In order to alter the crystal shape and the orientation of exposed facets, only a few strategies have been proposed to date. 22,23 The addition of oleylamine or increasing the concentration of iodide-ions in the precursor solution: both were shown to induce the growth of cuboid crystals with the (002) and (110) facets exposed.…”

“…13,14,17 There has been several reports on facet-dependent electronic behavior of CH3NH3PbI3 perovskites recently. [18][19][20] However, reported studies mainly focused on the typical rhombo-dodecahedral (or shortly, rhombic) shape of CH3NH3PbI3 single crystals, which presents natural facets oriented along the (200) and (112) crystallographic planes. On the other hand, the electronic behavior of the structurally important (002) plane, which slice the perovskite structure along the octahedral diagonals, remains largely unexplored.…”

Polarization‐Dependent Photoluminescence of a Highly (100)‐Oriented Perovskite Film

“…[14] In this regard, it is reasonable to assume that the anisotropic properties of the device could be affected by the anisotropic charge carrierrelated properties. Based on the related reports [13,15] and the growth pattern of the oriented perovskite itself, we expect the optical absorption of the oriented perovskite thin films to be anisotropic along the growth direction. To examine the growthorientation-dependent absorption of the oriented perovskite thin films, a spectroscopic technique employing variable excitation light polarization is necessary.…”

Growth and Characterization of Radiation Sensors Based on Single Crystals of Hybrid Metal–Organic Methylammonium Lead Bromide and Iodide Perovskite

“…The behavior of the current under the bias between -28 and -33 V (Figure 7a) can be attributed to a nonuniform thickness and charge-carrier mobility including migration of Br − and MA + ions. [10] The two Au-polycrystalline sample contacts display a narrower overlap in the I-V curves ( Figure S2c,d, Supporting Information).…”

“…Hence, the intrinsic charge-carrier mobility, electron-phonon coupling, and diffusion of ions are affected by anisotropy of crystal structure (facet orientation), lattice distortions, surface terminations (PbX 2 -rich), and the presence of defects including impurities in a solvent and solutes. [10] The research on application of MAPbX 3 semiconductor material in X-ray radiation screening and imaging is at its early stage. Polycrystalline MAPbI 3 films, [11] but more importantly single crystals of MAPbBr 3 [12][13][14] and MAPbI 3 , [15] perform comparably to the CdTe and (Cd,Zn)Te sensor materials.…”