High Curvature PEDOT:PSS Transport Layer Toward Enhanced Perovskite Light‐Emitting Diodes

Abstract

The rapidly developed metal halide perovskite light‐emitting diodes (PeLEDs) are considered as a promising candidate for next‐generation display and illumination, but the unbalanced charge transport is still a hard‐treat case to restrict its efficiency and operational stability. Here, a high curvature PEDOT:PSS transport layer is demonstrated via the self‐assembly island‐like structures by the incorporation of alkali metal salts. Benefiting from the dielectric confinement effect of the high curvature surface, the modified CsPbBr3‐based PeLEDs present a 2.1 times peak external quantum efficiency (EQE) from 6.75% to 14.23% and a 3.3 times half lifetime (T50) from 3.96 to 13.01 h. Besides, the PeLEDs show high luminance up to 44834 cd m−2. Evidently, this work may provide a deep insight into the structure‐activity relationship between the micro‐structures at the PEDOT:PSS/perovskite interface and the performance of PeLEDs, and crack the codes for ameliorating the performance of PeLEDs via interfacial micro‐structured regulation.

Inorganic Cu2ZnSnS4 hole transport layer for perovskite light-emitting diodes

“…The underlying CZTS nanocrystal films determine the quality of the perovskite (PVK) emission layer (EML). 37–39 The photoluminescence (PL) spectra of FAPbBr 3 quantum dots (QDs) on the W 0 /W 1 /W 2 films in Fig. 2a exhibit a homogeneous emission at 526 nm and a distinguishing attenuation of peak intensity.…”

“…2g), the obtained parameters are summarized in Table S1 †. The variation of FWHM broadening with temperature is described by formula (3): 37,40,41 Γ ( T ) = Γ 0 + Γ AC + Γ LO = Γ inh + γ AC T + γ LO /[e E LO / k B T − 1]where Γ 0 is an intrinsic inhomogeneous broadening term associated with material composition, size, and shape. Γ AC results from acoustic scattering and Γ inh stems from optical phonon scattering, both contributing to homogeneous PL emission broadening.…”

Low-dimensional nanomaterial-enabled efficient and stable perovskite light-emitting diodes: recent progress and challenges

“…[21][22][23][24] In addition, the mismatched charge transport capability of the charge transport layers and the inequal charge injection level between the upper and lower interface of perovskite film will lead to serious carrier accumulation, and the accumulated carriers can be easily trapped by defects at the interface, resulting in nonradiative losses of carriers and the declining lifetime of PeLEDs. [25][26][27][28][29][30][31] The electric-field-induced ion migration also plays a decisive role as the diffusion of metal elements from the metal oxide electrode/transport layer to the emitting layer will cause serious luminescence quenching and the efficiency and stability of devices can be seriously restricted. [32][33][34] Recently, low-dimensional nanomaterials (LDNMs) have been widely used in perovskite optoelectronic devices because of their unique surface effect, 35 quantum size effect, [36][37][38] quantum tunneling effect 39 and size-dependent optoelectronic properties.…”