Near-Infrared and Visible-range Optoelectronics in 2D Hybrid Perovskite/Transition Metal Dichalcogenide Heterostructures

TL;DR

This paper demonstrates how 2D perovskite/TMD heterostructures can be engineered to extend optoelectronic functionalities into the near-infrared and visible spectrum, enabling tunable band alignments for diverse applications.

Contribution

It introduces a method to tailor interfacial band alignments in 2D perovskite/TMD heterostructures for enhanced optoelectronic device performance.

Findings

Tunable type-II, type-I, and type-III band alignments achieved.

Significant strain tolerance demonstrated for flexible applications.

Enhanced photodetection and photovoltaic capabilities shown.

Abstract

The application of ultrathin two-dimensional (2D) perovskites in near-infrared and visible-range optoelectronics has been limited owing to their inherent wide bandgaps, large excitonic binding energies and low optical absorption at higher wavelengths. Here, we show that by tailoring interfacial band alignments via conjugation with low-dimensional materials like monolayer transition metal dichalcogenides (TMD), the functionalities of 2D perovskites can be extended to diverse, visible-range photophysical applications. Based on the choice of individual constituents in the 2D perovskite/TMD heterostructures, our first principles calculations demonstrate widely tunable type-II band gaps, carrier effective masses and band offsets to enable an effective separation of photogenerated excitons for enhanced photodetection and photovoltaic applications. In addition, we show the possibilities of achieving a type-I band alignment for recombination based light emitters as well as a type-III configuration for tunnelling devices. Further, we evaluate the effect of strain on the electronic properties of the heterostructures to show a significant strain tolerance, making them prospective candidates in flexible photosensors.