Zn doped MAPbBr₃ single crystal with advanced structural and optical stability achieved by strain compensation

Abstract

Strain compensation in a Zn doped MAPbBr3 single crystal under light illumination gives rise to improved photostability in terms of temperature and time to the benefit of photodetector.

Strain Engineering in Halide Perovskites

“…Alloying with different sizes of ions adjusts the tolerance factor of the material towards the stable range of the cubic phase. 35,71 The improved fit of ions within the lattice 41,46 suppresses degradation by polymorphism, vacancy, and defect formation, 44,62,72,73 as well as increasing carrier mobility and lifetime. 35,74 Increasing the effective radius of the A cation by incorporating large cations stabilizes compressively strained materials; for example, the addition of ethylammonium to MAPbI 3 (t < 1) 41,75 increases t (Table 1, I, A).…”

“…78 Stabilization via B site substitution has been shown with the substitution of Sn 2+ in MAPb(IBr) 3 , 79 Cd 2+ in Cs 0.05 MA 0.15 FA 0.8 PbI 2.55 Br 0.45 , 62 and Zn 2+ in MAPbBr 3 and MAPbI (3−x) Cl x . 72,73 The tolerance factor can be increased with the incorporation of smaller X anions such as the substitution of some I − with Cl − in Cs 0.05 MA 0.15 FA 0.8 PbI 2.55 Br 0.45 62 (Table 1, I, A). Tensile strain from large A cations can be relaxed with the formation of a two-dimensional perovskite structure.…”

“…Alloying with different sizes of ions adjusts the tolerance factor of the material towards the stable range of the cubic phase. , The improved fit of ions within the lattice , suppresses degradation by polymorphism, vacancy, and defect formation, ,,, as well as increasing carrier mobility and lifetime. , …”

“…Adding smaller B ions will increase the tolerance factor, relaxing compressive strain by reducing the lattice size to create smaller A sites . Stabilization via B site substitution has been shown with the substitution of Sn 2+ in MAPb­(IBr) 3 , Cd 2+ in Cs 0.05 MA 0.15 FA 0.8 PbI 2.55 Br 0.45 , and Zn 2+ in MAPbBr 3 and MAPbI (3– x ) Cl x . , The tolerance factor can be increased with the incorporation of smaller X anions such as the substitution of some I – with Cl – in Cs 0.05 MA 0.15 FA 0.8 PbI 2.55 Br 0.45 (Table , I, A).…”

Self‐Structural Healing of Encapsulated Perovskite Microcrystals for Improved Optical and Thermal Stability

“…[21][22][23] In order to obtain a stable device with high effi ciency, significant research efforts have been devoted to opti mize the property of perovskite materials, such as deposition techniques, composition regulating, as well as surface modi fication. For instance, using vaporphase conversion growth method for improved crystal quality of the material; or doping different ions into A, B, and X sites [24] for relieved crystal stress or increased chemical bonds strength. [25] Nevertheless, these methods require atomiclevel adjustment which is hard to con trol and will increase the cost of device production.…”