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Abstract Quasi‐2D Ruddlesden–Popper halide perovskites with a large exciton binding energy, self‐assembled quantum wells, and high quantum yield draw attention for optoelectronic device applications. Thin films of these quasi‐2D perovskites consist of a mixture of domains having different dimensionality, allowing energy funneling from lower‐dimensional nanosheets (high‐bandgap domains) to 3D nanocrystals (low‐bandgap domains). High‐quality quasi‐2D perovskite (PEA)2(FA)3Pb4Br13films are fabricated by solution engineering. Grazing‐incidence wide‐angle X‐ray scattering measurements are conducted to study the crystal orientation, and transient absorption spectroscopy measurements are conducted to study the charge‐carrier dynamics. These data show that highly oriented 2D crystal films have a faster energy transfer from the high‐bandgap domains to the low‐bandgap domains (<0.5 ps) compared to the randomly oriented films. High‐performance light‐emitting diodes can be realized with these highly oriented 2D films. Finally, amplified spontaneous emission with a low threshold 4.16 µJ cm−2is achieved and distributed feedback lasers are also demonstrated. These results show that it is important to control the morphology of the quasi‐2D films to achieve efficient energy transfer, which is a critical requirement for light‐emitting devices.
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Catalyst‐Free and Morphology‐Controlled Growth of 2D Perovskite Nanowires for Polarized Light Detection
Abstract Ruddleson–Popper (RP) perovskites have emerged as a class of material inheriting the superior optoelectronic properties of two materials: perovskites and 2D materials. The large exciton binding energy and natural quantum well structure not only make these materials ideal platforms to study light–matter interactions but also render them suitable for fabrication of various functional optoelectronic devices. Nanoscale structuring and morphology control have led to semiconductors with enhanced functionalities. Nanowires of semiconducting materials are extensively used for important applications like lasing and sensing. However, catalyst and template‐free scalable growth of nanowires of 2D perovskites has remained elusive. In this paper, a facile approach for morphology‐controlled growth of nanowires of 2D perovskite, (BA)2PbI4, is demonstrated. Additionally, it is shown that the photoluminescence (PL) from the nanowires is highly polarized with a polarization ratio as large as ≈0.73, which is one of the largest reported for perovskites. It is further shown that the photocurrent from the hybrid nanowire/graphene device is also sensitive to the polarization of the incident light with the photocurrent anisotropy ratio of ≈3.62 (much larger than the previously reported value of 2.68 for perovskites), thus demonstrating the potential of these nanowires as highly efficient photodetectors for polarized light.
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- Award ID(s):
- 1807233
- PAR ID:
- 10458321
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Optical Materials
- Volume:
- 7
- Issue:
- 15
- ISSN:
- 2195-1071
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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