Enhanced Coverage of All‐Inorganic Perovskite CsPbBr₃ through Sequential Deposition for Green Light‐Emitting Diodes

Abstract

Film morphology has a major influence on the performance of halide perovskite semiconductors, where poor coverage and pinholes are generally detrimental and result in undesirable current leakage. All‐inorganic cesium lead bromide (CsPbBr3) has an advantage of improved stability especially under device operation, but the low solubility of the ionic precursor CsBr limits the coverage of the solution‐processed film. To tackle this, a sequential deposition technique is proposed whereby PbBr2 is first deposited on a planar substrate prior to exposure to a CsBr solution to initiate conversion to the desired CsPbBr3 phase. This approach essentially nullifies the solubility problem of CsBr and the final perovskite film coverage now chiefly depends on the initial PbBr2 concentration and the duration of exposure to the CsBr solution. With over 90 % film coverage achieved, a proof of concept perovskite light‐emitting diode (PeLED) with green emission at 527 nm has also been achieved, thereby demonstrating the feasibility of this methodology for future device fabrication.

Efficient Quantum Dot Light-Emitting Diodes Based on Trioctylphosphine Oxide-Passivated Organometallic Halide Perovskites

“…However, the small peak at 14.4° of samples indicates that a small amount of PbBr 2 was present in the perovskite films, which was always located at the grain boundary. 55 As the concentration of TOPO increases, the gradual disappearance of that small shoulder may be attributed to the action of TOPO on PbBr 2 . Furthermore, the FWHM of the diffraction peak for these TOPO-treated samples remarkably becomes wider than that of the Control, meaning that the smaller QDs are obtained with the use of TOPO.…”

Anisotropic In Situ Strain‐Engineered Halide Perovskites for High Mechanical Flexibility

“…The PEDOT:PSS interlayer was used in this two‐step deposition method to help the formation of a loosely packed first layer for easy penetration of the second precursor through open channels of the first layer and thus for dense halide films as reported. [ 48,49 ] It should be mentioned that there was no fracture observed on the surface of PEDOT:PSS layer after the bending fracture evaluation up to the maximum bending strain ε b of ≈2.0% as shown in Figure S12, Supporting Information.…”

Improved photoelectric performance of all-inorganic perovskite through different additives for green light-emitting diodes

“…1(b), where the energy levels of inorganic materials and the work-function of electrodes are cited from the literature. 29,30,32,39 The UPS data of pure CsPbBr 3 , CsPbBr 3 -PEO and CsPbBr 3 -PEO-PVP lms are showed in Fig. S7.…”