Vapor-Phase Incommensurate Heteroepitaxy of Oriented Single-Crystal CsPbBr₃ on GaN: Toward Integrated Optoelectronic Applications

Abstract

Integrating metallic halide perovskites with established modern semiconductor technology is significant for promoting the development of application-level optoelectronic devices. To realize such devices, exploring the growth dynamics and interfacial carrier dynamics of perovskites deposited on the core materials of semiconductor technology is essential. Herein, we report the incommensurate heteroepitaxy of highly oriented singlecrystal cesium lead bromide (CsPbBr 3 ) on c-wurtzite GaN/ sapphire substrates with atomically smooth surface and uniform rectangular shape by chemical vapor deposition. The CsPbBr 3 microplatelet crystal exhibits green-colored lasing under room temperature and has a structural stability comparable with that grown on van der Waals mica substrates. Time-resolved photoluminescence spectroscopy studies show that the type-II CsPbBr 3 −GaN heterojunction effectively enhances the separation and extraction of free carriers inside CsPbBr 3 . These findings provide insights into the fabrication and application-level integrated optoelectronic devices of CsPbBr 3 perovskites.

In‐Situ and Reversible Enhancement of Photoluminescence from CsPbBr3 Nanoplatelets by Electrical Bias

“…The CsPbBr 3 nanoplatelets were employed by virtue of the monocrystalline nature to avoid the impacts from grain boundaries/organic impurities and its potential in developing the miniaturized optoelectonic devices. [ 20,21 ] The introduction of the insulating layer (PMMA) aimed to eliminate the influence of injected charges. The single crystalline nature and the uniform composition distribution of the CsPbBr 3 nanoplatelets were confirmed by the energy‐dispersive X‐ray spectroscopy (EDS) and X‐ray diffraction (XRD) characterization measurements (Figure S1, Supporting Information).…”

Excellent Excitonic Photovoltaic Effect in 2D CsPbBr3/CdS Heterostructures

“…Besides the fact that the PL intensity obviously decreases at room temperature, we notice that the PL signal of the A exciton at the heterojunction decays to ≈10% of the isolated CdS, while the B exciton signal decays to ≈2% of the pure CsPbBr 3 . Such giant PL quenching effect demonstrates that most photoinduced charge carriers are separating, including an efficient electron transfer, [ 37 ] at the interface of the heterojunction. Figure 4b displays the temperature‐dependent PL curves of the heterojunction, which were fitted into an A exciton peak (olive color) and a B exciton peak (violet color).…”

Graphoepitaxy of Large Scale, Highly Ordered CsPbBr3 Nanowire Array on Muscovite Mica (001) Driven by Surface Reconstructed Grooves

“…The PL lifetime shows a reciprocal dependence on the pump fluence, which is usually considered as the feature of free‐carrier recombination or Auger recombination. [ 43,50 ] The I PL ( t = 0) is nearly linear to the excitation density and the power law (≈1.03) does not decrease with increasing excitation density. Also, the carrier density (4.1 × 10 13 cm −3 –4.95 × 10 15 cm −3 ) is significantly lower than the threshold density of Auger recombination reported in previous literatures.…”