Low‐Temperature Crystallized and Flexible 1D/3D Perovskite Heterostructure with Robust Flexibility and High EQE‐Bandwidth Product

Abstract

All-inorganic perovskite cesium lead triiodide (CsPbI 3 ) has attracted much attention among the perovskite family due to its excellent optoelectronic properties and chemical stability. However, the high-temperature crystallization process makes CsPbI 3 less compatible with commercially flexible substrates, limiting its application into flexible optoelectronics. Here, a cation of 1-(3-aminopropyl)-2pyrrolidinone (APP) is reported that can form 1D (APP)PbI 3 perovskite as templates, and significantly reduce the CsPbI 3 black-phase transition energy with a low annealing temperature of 75 °C, which further enables a flexible (APP)PbI 3 /γ-CsPbI 3 (1D/3D) heterostructure photodetector on ITO/ PET substrate. A high external quantum efficiency (EQE) greater than 2377% is observed along the orientated 1D/3D heterostructure. The high gain and low noise result in a high specific detectivity (D*) over 10 12 Jones under −0.6 V low bias. The optimized device structure brings a high EQE × bandwidth product of 119 kHz under a low driving bias. Due to the high toughness of orientated APP + ions and the face-connected [PbI 3 ] − chains structure as a strong energy absorber, the flexible photodetector also shows excellent phase stability and impressive flexibility, remaining >90% initial responsivity after over 20 000 times bending with potential flexible imaging application in harsh environments.

Differential perovskite hemispherical photodetector for intelligent imaging and location tracking

“…The addition of NGAI can effectively slow down the film crystallization rate by wrapping the [PbI 6 ] 4− in solution (Figs. 1e, f ) 36 , 39 , which results in a larger grain than that film without NGAI (Supplementary Fig. 4e ).…”

Recent advance of high-quality perovskite nanostructure and its application in flexible photodetectors

“…The performance parameters still fall short of the anticipated levels when the device undergoes deformation. Existing studies either involved a limited number of bending cycles at large bending radii or lacked comprehensive examinations of the tensile properties for flexible devices [135][136][137][151][152][153][154][155][156][157][158][159][160][161][162][163]. This limitation arises from the inevitable formation of cracks in the perovskite functional films during repeated bending processes, leading to accelerated degradation of the perovskite materials and damage to device performance.…”

“…In order to solve the problem of difficulty in growing CsPbI 3 films on flexible ITO/PET substrates due to the hightemperature crystallization process. Qu et al proposed a strategy to greatly reduce the annealing temperature of CsPbI 3 films using 1D (APP)PbI 3 perovskite as templates and the flexible 1D/3D (APP)PbI 3 /γ-CsPbI 3 heterojunction PDs brought high EQE of 2377% under a low external bias [163]. Figure 14(d)(i) showed the setup for bending tests with a 532 nm laser as the excitation light.…”

Crystalline–Amorphous Heterojunction for a Metal Halides Single Crystals X‐Ray Detector with Substantially Increased Sensitivity

“…However, the traditional stepwise solution method or epitaxial growth still has substantial limitations. [43][44][45] For example, the requirement to ensure that the growth solution of the latter crystals does not destroy the former, the lattice constants match as closely as possible, etc. [46,47] To conclude, optimization of crystal structure and device structure is currently the commonly employed and most effective strategy to overcome ion migration in MHs SCs to reduce device noise.…”

“…However, the traditional stepwise solution method or epitaxial growth still has substantial limitations. [ 43–45 ] For example, the requirement to ensure that the growth solution of the latter crystals does not destroy the former, the lattice constants match as closely as possible, etc. [ 46,47 ]…”