Can B-Site Doping or Alloying Improve Thermal- and Phase-Stability of All-Inorganic CsPbX<sub>3</sub> (X = Cl, Br, I) Perovskites?

Swarnkar, Abhishek; Mir, Wasim J.; Nag, Angshuman

doi:10.1021/acsenergylett.7b01197

Cited by 435 publications

(454 citation statements)

References 39 publications

(60 reference statements)

Supporting

Mentioning

421

Contrasting

Unclassified

Order By: Relevance

“…It has been demonstrated that the phase stabilization of perovskite semiconductors could be achieved by controlling the octahedral tilting via partially substituting Pb 2+ with other metal ions. For instance, substitution of smaller Mn 2+ stabilizes the cubic α-CsPbI 3 phase by reducing the octahedral rotation or tilting via a decrease in the bond angle of Pb–I–Pb below 180°, which is along the interconnected neighboring PbX 6 octahedra through the bridging halide ion 31 . In the present case, a similar octahedral tilting (enhanced) results in the phase stabilization of low-symmetry Cs 4 Pb(Br/Cl) 6 upon Mn 2+ incorporation.…”

Section: Resultsmentioning

confidence: 99%

Probing molecule-like isolated octahedra via phase stabilization of zero-dimensional cesium lead halide nanocrystals

et al. 2018

View full text Add to dashboard Cite

Zero-dimensional (0D) inorganic perovskites have recently emerged as an interesting class of material owing to their intrinsic Pb2+ emission, polaron formation, and large exciton binding energy. They have a unique quantum-confined structure, originating from the complete isolation of octahedra exhibiting single-molecule behavior. Herein, we probe the optical behavior of single-molecule-like isolated octahedra in 0D Cesium lead halide (Cs4PbX6, X = Cl, Br/Cl, Br) nanocrystals through isovalent manganese doping at lead sites. The incorporation of manganese induced phase stabilization of 0D Cs4PbX6 over CsPbX3 by lowering the symmetry of PbX6 via enhanced octahedral distortion. This approach enables the synthesis of CsPbX3 free Cs4PbX6 nanocrystals. A high photoluminescence quantum yield for manganese emission was obtained in colloidal (29%) and solid (21%, powder) forms. These performances can be attributed to structure-induced confinement effects, which enhance the energy transfer from localized host exciton states to Mn2+ dopant within the isolated octahedra.

show abstract

Section: Resultsmentioning

confidence: 99%

Probing molecule-like isolated octahedra via phase stabilization of zero-dimensional cesium lead halide nanocrystals

et al. 2018

View full text Add to dashboard Cite

show abstract

“…It has also stimulated a widespread application of halide metal perovskites in other fields, such as light-emitting diodes, field-effect transistors, detectors, and lasers. [25,[56][57][58] The A 2 B′B″X 6 crystal structure provides an avenue for easier substitution and incorporation of different metal cations with different oxidation states in the B-site, various organic and inorganic species in the A-site, and a variation of halide composition in the X-site. Addressing the toxicity issues in these compounds by a careful and strategic replacement of Pb 2+ with other nontoxic candidate elements represents a promising direction to fabricate lead-free optoelectronic devices.…”

Section: Introductionmentioning

confidence: 99%

Progress of Lead‐Free Halide Double Perovskites

Igbari

Wang

Liao

2019

Advanced Energy Materials

379

305

View full text Add to dashboard Cite

Although impressive performance has been obtained, PSCs are still far from commercial or real-life availability due to serious issues such as toxicity [15,16] and poor stability to heat, [17] oxygen, [18] moisture, [19,20] electric field, [21] and light. [18,22] The toxic nature of hybrid organic-inorganic lead halide perovskites has been traced to the presence of Pb in its chemical composition. [15,16,[23][24][25] Pb 2+ readily dissolves in water (e.g., rain water) to form a toxic solution capable of causing serious environmental pollution, harmful to human beings and the ecosystem. Besides their sensitivity to moisture, oxygen, light, electric field, or thermal stress, an existing self-degradation pathway [26,27] is also a big issue in hybrid organic-inorganic lead halide perovskites. Mixed-halide and mixed-cation perovskites have been investigated to address these issues. [28][29][30][31][32] The group IV elements, tin (Sn) [23,[33][34][35] and germanium (Ge), [34,36] have been employed as the replacements for Pb. However, the device performance through this approach has fallen short of the Pb-based ones. For example, the PCEs reported for Sn-based perovskite solar cells are usually less than 10%. [23,[33][34][35][37][38][39][40] In addition, the easy oxidation of Sn and Ge from the +2 state to the +4 state due to their high energy 5s and 4s orbitals makes them less promising for application in stable and long-term PSCs. [41] High throughput calculations also demonstrate that these substitutions are likely to compromise the ideal optoelectronic properties of MAPbI 3 . [42,43] Furthermore, low dimensional (e.g., 2D, 1D, and 0D) perovskites have also been used to address the stability issues in PSCs. [44][45][46][47][48] Recently, a stabilized PCE of 21.7% resulting from a 2D/3D bilayer PSC was reported. [49] However, the highest certified PCE in a 2D-only planar PSC is 15.3%, [50] which is far below that of their 3D perovskite-based counterparts. It thus stimulates the interest to develop new classes of materials which can solve the issues of toxicity and stability while still maintaining the fascinating properties of lead-based perovskite materials.Recent theoretical calculations demonstrate that a halide double perovskite structure, A 2 B′B″X 6 , which could be formed through a replacement of two toxic Pb 2+ in the crystal lattice with a pair of nontoxic heterovalent (i.e., monovalent and trivalent) metal cations, is a promising alternative to realize high-performance, lead-free, and stable PSCs. [51,52] Although, spectroscopic limited maximum efficiency (SLME) calculations revealed an efficiency limit less than 8% for the most prominent member www.advancedsciencenews.com double perovskites with a vacancy ordered structure. [88] In particular, the unit cell axis of Cs 2 AgBiBr 6 is given to be ≈11.25 Å, [25] which is two times larger than that of MAPbBr 3 (≈5.92 Å). [89] Both Ag + and Bi 3+ occupy the B-site of the crystal lattice with slightly varied metal-halide bond lengths. The dissimilar bond lengths st...

show abstract

“…[24] However, color tunability and PLQY improvement were typically achieved only in nanostructures, [25] including inorganic perovskite nanocrystals, [26][27][28][29][30][31] probably due to the low doping limit that is not sufficient to compensate for the abundant defects in bulk. [24] However, color tunability and PLQY improvement were typically achieved only in nanostructures, [25] including inorganic perovskite nanocrystals, [26][27][28][29][30][31] probably due to the low doping limit that is not sufficient to compensate for the abundant defects in bulk.…”

mentioning

confidence: 99%

Broadband Extrinsic Self‐Trapped Exciton Emission in Sn‐Doped 2D Lead‐Halide Perovskites

et al. 2018

View full text Add to dashboard Cite

Metal-halide perovskites represent a class of promising light absorbers for efficient solar cells. [1][2][3][4][5] The propensity of perovskite films for low-cost solution processing also encourages scientists to explore potential applications beyond solar cells. [6][7][8][9] In particular, as emitters, perovskites exhibit intriguing luminescent properties such as narrowband emission, spectral tunability, and high quantum efficiency, which enables applications in the microlasers and light-emitting diodes (LEDs). [10][11][12][13] The luminescence efficiency of perovskites generally relies on nanostructures that can spatially confine excitons, and consequently reduce the possibility of nonradiative recombination during the carrier/ exciton migration. However, nanocrystals, due to boundary scattering of carriers, generally face the problem of poor charge transport, which is undesirable for LED performance. 2D perovskites, where bulky organic layers and inorganic layers are alternately and periodically arranged, feature natural quantum-well structures. This quantum-well structure is regarded as promising LED emitters for decades. [14][15][16] However, low photoluminescence quantum yields (PLQYs, typically < 1%) of 2D perovskites at room temperature is a bottleneck to achieving high-performance LEDs. [17] The low PLQYs may be attributed to insufficient confinement of Wannier type excitons within the inorganic layers [18] as suggested by the long charge-carrier/exciton diffusion length (60 nm). [19] Engineering crystal structures of low-dimensional (0D to 2D) perovskites by employing suitable organic ammonium cations is the predominant methods for the tuning of luminescence, both in spectral coverage and efficiency. [20,21] In these cases, severe structural distortion of metal halide octahedra is a common feature because of the size mismatch between organic and inorganic components, which results in potential fluctuations. [22,23] Such fluctuations of potential within an inorganic layer of perovskite sometimes, but not always, [20,21] slow the diffusion of carriers or excitons, and consequently induce self-trapped excitons (STEs), which represents a type of bound states for efficient radiative recombination. However, the occurrence of exciton self-trapping in semiconductors is the exception rather than the rule. [24] In parallel, compositional engineering As emerging efficient emitters, metal-halide perovskites offer the intriguing potential to the low-cost light emitting devices. However, semiconductors generally suffer from severe luminescence quenching due to insufficient confinement of excitons (bound electron-hole pairs). Here, Sn-triggered extrinsic self-trapping of excitons in bulk 2D perovskite crystal, PEA 2 PbI 4 (PEA = phenylethylammonium), is reported, where exciton self-trapping never occurs in its pure state. By creating local potential wells, isoelectronic Sn dopants initiate the localization of excitons, which would further induce the large lattice deformation around the impurities to accommodate the se...

show abstract

Can B-Site Doping or Alloying Improve Thermal- and Phase-Stability of All-Inorganic CsPbX₃ (X = Cl, Br, I) Perovskites?

Cited by 435 publications

References 39 publications

Probing molecule-like isolated octahedra via phase stabilization of zero-dimensional cesium lead halide nanocrystals

Probing molecule-like isolated octahedra via phase stabilization of zero-dimensional cesium lead halide nanocrystals

Progress of Lead‐Free Halide Double Perovskites

Broadband Extrinsic Self‐Trapped Exciton Emission in Sn‐Doped 2D Lead‐Halide Perovskites

Contact Info

Product

Resources

About

Can B-Site Doping or Alloying Improve Thermal- and Phase-Stability of All-Inorganic CsPbX3 (X = Cl, Br, I) Perovskites?

Cited by 435 publications

References 39 publications

Probing molecule-like isolated octahedra via phase stabilization of zero-dimensional cesium lead halide nanocrystals

Probing molecule-like isolated octahedra via phase stabilization of zero-dimensional cesium lead halide nanocrystals

Progress of Lead‐Free Halide Double Perovskites

Broadband Extrinsic Self‐Trapped Exciton Emission in Sn‐Doped 2D Lead‐Halide Perovskites

Contact Info

Product

Resources

About

Can B-Site Doping or Alloying Improve Thermal- and Phase-Stability of All-Inorganic CsPbX₃ (X = Cl, Br, I) Perovskites?