Perovskite MAPb(Br1−Cl )3 single crystals: Solution growth and electrical properties

Beyond Tristimulus Color Vision with Perovskite-Based Multispectral Sensors

“…The optical constants of the required perovskite materials are calculated using energy shift modeling, where the optical constants of experimentally prepared halide perovskite films of MAPbCl 3 , MAPbBr 3 , and MAPbI 3 are used as input parameters. − In this method, an arbitrary composition of mixed-halide perovskite is synthesized from a pair of known optical functions, leading to an optical spectrum of the resultant compositions, which is red­(or blue)-shifted so that the band gap energies match well with that of the target composition. , The dielectric constants (ε 1 and ε 2 ), refractive index ( n ), and extinction constants of perovskite materials determined with the aid of the energy shift model are depicted in Figure . The results are in very good agreement with the experimentally measured data. , Such perovskite alloys with tunable band gaps can be prepared with the aid of solution-processed and vapor deposition methods. − …”

MAPb(Br1–xClx)3 Hybrid Perovskite Materials for Direct X-ray Detection

“…The results partially corroborate previous works on this material. 2,19,20 Optoelectronic evaluation, meticulously performed in X-ray medical radiography conditions, backed up by a systematic crystal batch production and coupled with other characterization techniques, reveals the high quality of synthesized MAPb(Br 1−x Cl x ) 3 SCs, exhibiting no hysteresis during current−voltage measurements and a negligible conductivity drift. This linked to the optimized growth nature of MAPb(Br 1−x Cl x ) 3 SCs produced by our method, with few and reproducible defect structures.…”

“…On the other hand, for MAPbCl 3 (%Cl sol = 100), as the growth cannot be carried out in pure DMF, a DMF/DMSO mixture (3:7 in volume) was used with a ramp of 1.6 °C h −1 . 20 The reduction of the temperature ramp (1/5) was more important than that of the solubility−temperature ratio (1:2) to ensure that the solution stays in the reduced metastable zone and avoid significant spontaneous nucleation in Cl-rich solutions. It is because nucleation would become predominant in growth conditions used for MAPbBr 3 that we limited our study to rather low Cl contents, in order to grow mm-sized crystals of different Cl contents but under similar growth conditions.…”

“…15 Also, in many of these studies mixed halide crystals are grown in DMF/DMSO (dimethyl sulfoxide) mixtures of varying proportions. 20,22 While it makes sense to compensate the lower solubility of species with chloride in DMF by increasing the DMSO proportion with increasing Cl content, it could have an adverse effect on the grown crystal properties, as it has been claimed that DMSO favors the formation of defects (MA + vacancies V MA ) in MAPbBr 3 when it is used in large proportion (>3%). 24 While the performance of MAPb(Br 1−x Cl x ) 3 SCs has largely been assessed for γ-ray detection, 2,4,19,25 its performance as an X-ray detector, and specifically for radiography applications, has been seldom reported.…”

Composition Engineering of Perovskite Single Crystals for High‐Performance Optoelectronics

“…Because a low electronegativity (Cl > Br > I) increases the covalent properties of BX bonding and therefore brings a decrease in the bandgap. Taking MAPbI 3 as an example, the absorption edge of the MAPbI 3 can be continuously tuned from the NIR to UV range by varying the halide composition from I − to Br − to Cl − , [ 2,31,38 ] and their corresponding bandgap is widely changed from 1.5 to 2.9 eV, as illustrated in Figure a. Additionally, both alloying of MA with FA and substituting other metal ions into the Pb‐site (like Sn 2+ or Bi 3+ ) can lead to red‐shifting of the absorption range of the MAPbI 3 .…”