Characterization of an abnormal photoluminescence behavior upon crystal-phase transition of perovskite CH₃NH₃PbI₃

Abstract

Solution-processed hybrid perovskite of CH3NH3PbI3 (MAPbI3) exhibits an abnormal luminescence behavior at around the tetragonal-orthorhombic phase transition temperature. The combination of time resolved photoluminescence (PL), variable excitation power PL, and variable-temperature X-ray diffraction (XRD) allows us to clearly interpret the abnormal luminescence features in the phase transition region of MAPbI3. Both PL and XRD results unambiguously prove the coexistence of the tetragonal and orthorhombic phases of MAPbI3 in the temperature range of 150 to 130 K. The two luminescence features observed in the orthorhombic phase at T < 130 K originate from free excitons and donor-acceptor-pair (DAP) transitions, respectively. The comprehensive understanding of optical properties upon phase transition in MAPbI3 will benefit the development of new optoelectronic devices.

Inhibition of a structural phase transition in one-dimensional organometal halide perovskite nanorods grown inside porous silicon nanotube templates

“…42,[46][47][48][49][50]54,55,[60][61][62][63][64] Furthermore, there are certain publications describing direct evidences to the existence of two phases at low temperatures, 48,[65][66][67] which are also supported by our own lowtemperature TEM electron diffraction experiments reported in the supplementary information. Hence, the most significant finding of this work is the inhibition of the phase transition in 1D perovskite nanorods having diameter below ~ 100-150 nm.…”

“…Let us emphasize that quite similar, temperature-dependence PL-based experimental results for bulk perovskites, were reported by other groups. [46][47][48]61,66,72 Yet, neither discussion of the nature and the type of phase transition nor explanation of the discrepancy between the two observations, has been reported so far.…”

“…9) compared to kT below the phase transition temperature (kT < 14 meV), favors the transfer of excited free carriers (which are absorbed mainly in the orthorhombic phase) into the lower bandgap tetragonal phase followed by a radiative recombination (of electrons and holes) from that phase. 48,65,66 This mechanism significantly amplifies and broadens the PL emission from the tetragonal inclusions, despite that the fractional volume of this phase is practically very small below the phase transition temperature. …”

Polarization-selective three-photon absorption and subsequent photoluminescence inCsPbBr3single crystal at room temperature

“…9 In particular, the hybrid perovskites CH 3 NH 3 PbX 3 (MAPbX 3 ) have been extensively studied as potential PV materials, and MAPbX 3 -based PV cells have shown remarkable PCEs up to ∼ 20%. [8][9][10][11][12] While the actual device architecture is a critical factor in terms of technology evolution, the basic understanding of essential light-matter interaction in these perovskite materials is unarguably important for increasing the PCE as well as discovering other emerging optoelectronic properties such as radiation detection, 13 thermoelectricity, 14 lasing, 15 and light-emitting diodes.…”

Towards large-area perovskite solar cells: the influence of compact and mesoporous TiO2 electron transport layers

“…PL signals with a central wavelength at 769 nm [39] were acquired from The PL intensity as a function of location with respect to the gold electrode edge is plotted in figure 6(e). No PL signal was observed from the exposed perovskite region on which no gold layer is covered, indicating a complete degradation.…”