# Long‐Lived Photoluminescence of Photostable One‐Dimensional Picoperovskites

## TL;DR

Researchers found that one-dimensional perovskite crystals inside nanotubes emit long-lasting light, much longer than bulk perovskites.

## Contribution

The study reports extraordinarily long photoluminescence lifetimes in picoperovskites compared to bulk perovskites.

## Key findings

- Polarized micro-photoluminescence reveals bright emission with linear polarization along the bundle axis.
- Picoperovskites exhibit PL lifetimes of several hundred nanoseconds at low temperatures.
- The emission is redshifted compared to bulk perovskite samples with the same constituents.

## Abstract

We study one‐dimensional metal halide perovskite crystals encapsulated in single‐wall nanotubes, so‐called picoperovskites, using optical spectroscopy. Polarized micro‐photoluminescence (PL) reveals bright emission from aligned bundles of picoperovskites with clear linear polarization along the bundle axis. This emission is redshifted with respect to bulk perovskite samples using the same constituents. Temperature‐dependent, time‐resolved micro‐PL shows extraordinarily long PL lifetimes of the picoperovskites at low temperatures, reaching several hundred nanoseconds and exceeding those of bulk perovskites by two orders of magnitude.

We study one‐dimensional metal halide perovskite crystals encapsulated in single‐wall nanotubes, so‐called picoperovskites, using optical spectroscopy. Polarized micro‐photoluminescence (PL) reveals bright emission from aligned bundles of picoperovskites with clear linear polarization along the bundle axis. Time‐resolved micro‐PL at low temperatures shows lifetimes reaching several hundred nanoseconds, orders of magnitude higher than that of a reference bulk sample.© 2026 WILEY‐VCH GmbH