Emission wavelength control of CsPb(Br1-xClx)3 nanocrystals for blue light-emitting diode applications

All-inorganic materials, mixed halide perovskite (MHP) nanocrystals (NCs), have attracted considerable attention recently because of their excellent luminescence efficiencies and extraordinary physical properties, making them a promising material for next-generation lighting and full-color display. On the other hand, an essential development of blue-emitting devices rather than other color emitters has been hindered by their defect tolerance and quantum efficiency which are relatively lower than those of green-emitting NCs. Moreover, few studies have examined the synthesis and properties of blue-emitting MHP NCs or their applications to light-emitting diodes (LEDs). To solve these problems, this paper reports a facile and controllable way of producing emission wavelength tunable CsPb(Br1-xClx)(3) NCs using a fast and straightforward chemical treatment with the trimethylsilyl chloride (TMSC) additive. Structural and chemical analysis showed that the Cl content in the CsPb(Br1-xClx)(3) NCs could be modulated by TMSC addition without changing the morphologies. The photoluminescence emission peak wavelength of the CsPb(Br1-xClx)(3) NCs could be modulated from 515 to 416 nm by increasing the TMSC content. To this end, blue and green LEDs were successfully demonstrated by using the TMSC-treated CsPb(Br1-xClx)(3) NCs as an emissive layer, showing a controllable emission wavelength from 473 to 511 nm.

Automated summary

This paper presents a facile method to produce emission wavelength-tunable CsPb(Br1-xClx)(3) NCs using TMSC additive. The addition of TMSC allows for modulation of Cl content in NCs, adjusting the emission peak wavelength and enabling the fabrication of blue and green LEDs with controllable emission wavelengths.