# Laser-induced Phase-change Perovskite Photodetector Arrays for Optical Information Storage and Imaging

## TL;DR

This paper demonstrates a laser-controlled, reversible phase-change perovskite photodetector array capable of optical information storage and imaging, highlighting its potential for low-cost, flexible optoelectronic devices.

## Contribution

It introduces a vapor-deposited inorganic perovskite with reversible phase transitions used for rewritable optical memory and flexible imaging applications.

## Key findings

- Reversible phase transition between orthorhombic and cubic phases achieved.
- Laser-induced phase change enables optical data writing and erasing.
- Flexible perovskite photodetector arrays demonstrate optical memory and imaging capabilities.

## Abstract

The reversible phase transition between orthorhombic and cubic phases is demonstrated in all-inorganic perovskite CsPbIBr2 grown by a dual-source vapor-deposition method. The phase transition is actuated via heating and moisture exposure. The different crystal structures of two phases result in distinct optoelectronic properties including optical absorption, refractive index, and carrier transport. The perovskite photodetector array for the non-volatile rewritable optical memory application is further investigated. A near-infrared (NIR) laser ({\lambda} = 1064 nm) is used to selectively heat photodetector pixels through the photothermal effect of the interfacial Ag electrodes, resulting in an optically absorbing perovskite phase for the photodetectors. The locations of specific laser-written pixels can be read out by measuring their photocurrents, and the stored optical information can also be erased by moisture exposure. Finally, a proof-of-concept optical imaging application has been demonstrated using perovskite photodetector arrays fabricated on flexible PET substrates. These results show promising applications of vapor-deposited inorganic perovskite for optical memory and image sensors, with unique potential for low-cost manufacturing of large-area and/or flexible devices.

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Source: https://tomesphere.com/paper/1812.09267