Direct Vapor Growth of Perovskite CsPbBr₃ Nanoplate Electroluminescence Devices

Abstract

Metal halide perovskite nanostructures hold great promises as nanoscale light sources for integrated photonics due to their excellent optoelectronic properties. However, it remains a great challenge to fabricate halide perovskite nanodevices using traditional lithographic methods because the halide perovskites can be dissolved in polar solvents that are required in the traditional device fabrication process. Herein, we report single CsPbBr nanoplate electroluminescence (EL) devices fabricated by directly growing CsPbBr nanoplates on prepatterned indium tin oxide (ITO) electrodes via a vapor-phase deposition. Bright EL occurs in the region near the negatively biased contact, with a turn-on voltage of ∼3 V, a narrow full width at half-maximum of 22 nm, and an external quantum efficiency of ∼0.2%. Moreover, through scanning photocurrent microscopy and surface electrostatic potential measurements, we found that the formation of ITO/p-type CsPbBr Schottky barriers with highly efficient carrier injection is essential in realizing the EL. The formation of the ITO/p-type CsPbBr Schottky diode is also confirmed by the corresponding transistor characteristics. The achievement of EL nanodevices enabled by directly grown perovskite nanostructures could find applications in on-chip integrated photonics circuits and systems.

Strategy to overcome recombination limited photocurrent generation in CsPbX3 nanocrystal arrays

“…31 This observation is also consistent with the flux dependence of the photocurrent Figure 2(b) which implies that the photocurrent generation is limited by interband gap recombination. In the current device, the diffusion length can be estimated using an Einstein diffusion from field effect transistor measurements 34 and τ = 5 ns from our photocurrent decay measurements. This is much smaller than the electrode spacing (20 µm).…”

All‐Inorganic Hetero‐Structured Cesium Tin Halide Perovskite Light‐Emitting Diodes With Current Density Over 900 A cm−2 and Its Amplified Spontaneous Emission Behaviors

“…In order to estimate the EQE of the small area device, the EL and PL spectra of the CsSnBr 3 film were collected separately under the same measurement conditions. Assuming that the collection efficiency of the fiber optic system is equal and the absorption coefficient of the CsSnBr 3 film close to 100%, when PL and EL intensity is adjusted to equal, the ratio of the EQE to PLQY can be estimated as: , where q is the electron charge, P 400 is the pump power of the laser (400 nm), I is the current value, is the photon energy (here, ) . When the applied voltage is 5 V, the corresponding current in the device is about 3.8 mA and the corresponding P 400 about 175 µW, and then the calculated EQE is about 0.135%.…”

Metal Halide Perovskites: From Crystal Formations to Light‐Emitting‐Diode Applications

“…The inset is a photograph of an operating PeLED. Reproduced with permission . Copyright 2017, American Chemical Society.…”

“…MHP SCs can be also synthesized by CVD methods (Section ) . These MHP SCs can be easily applied to PeLED applications because SCs can be formed directly on the patterned electrodes (Figure e).…”

“…These MHP SCs can be easily applied to PeLED applications because SCs can be formed directly on the patterned electrodes (Figure e). Rectangular micrometer‐sized CsPbBr 3 SCs with lateral dimension ≈10 µm and thickness ≈100–500 nm were directly grown by CVD methods and placed between patterned ITO electrodes . Under an applied bias, lateral structural PeLEDs with micrometer‐sized CsPbBr 3 SCs showed pure green emission with an EL spectrum of 530–532 nm, FWHM of ≈22 nm, and EQE of 0.1–0.2% …”