# Ultrasensitive Circularly Polarized Photon Detectors Based on Chiral Two-Dimensional MoS2

## TL;DR

This paper introduces a new method to create ultrasensitive detectors for circularly polarized light using chiral 2D MoS2, which outperforms traditional 3D materials.

## Contribution

The study demonstrates a novel chirality transfer method in 2D MoS2, achieving record-high molar ellipticity and detection performance.

## Key findings

- Chiral 2D MoS2 films show a molar ellipticity of 108 deg·cm2/dmol, 3 orders of magnitude higher than 3D materials.
- Phototransistors with chiral 2D MoS2 channels achieve responsivity >102 A/W and anisotropy g-factor of 1.98.
- Reduced dimensionality enhances chirality transfer efficiency, enabling ultrasensitive circularly polarized photon detection.

## Abstract

Engineering chiral
optical and electronic properties
of materials
is interesting for applications in sensing and quantum information.
State-of-the-art chiral optoelectronic devices are mostly based on
three-dimensional (3D) and quasi-two-dimensional (2D) materials. Here
we demonstrate chiral 2D MoS2 with sub-nanometer thickness
via chirality transfer from l-/d-penicillamine (l-/d-PEN). We report a giant molar ellipticity of 108 deg·cm2/dmol in monolayer solid-state films,
up to 3 orders of magnitude higher than 3D chiral materials. Phototransistors
with chiral 2D MoS2 channels exhibit gate-tunable circularly
polarized light detection with responsivity of >102 A/W
and anisotropy g-factor of 1.98, close to the theoretical
maximum of 2.0. The reduced dimensionality magnifies the chirality
transfer efficiency, allowing realization of ultrasensitive detectors
for circularly polarized photons.