# Laser induced white emission and photocurrent of GaN nanoceramics

## TL;DR

This paper studies how gallium nitride nanoceramics emit white light and generate photocurrent when exposed to laser light, with potential uses in lighting and memory devices.

## Contribution

The study reveals hysteresis in laser-induced white emission and photocurrent in GaN nanoceramics, linking them to nonlinear charge carrier generation.

## Key findings

- Hysteresis was observed in laser-induced white emission and photocurrent with increasing and decreasing excitation power.
- Photoconductivity decreased with applied voltage until reaching saturation.
- The phenomena are linked to multiphoton ionization and show excitation threshold dependence.

## Abstract

The measurements of the optical properties of GaN nanoceramics are reported. In particular, the laser induced white emission (LIWE) and photocurrent (LIPC) were investigated. LIWE and LIPC was measured in closed cycles: forward, with increasing excitation power density, and backward, with decreasing excitation power density, with hysteresis occurring. The photoconductivity of the obtained nanoceramics was measured at different voltage biases, demonstrating a decrease in initial resistance with applied voltage until saturation was reached, after which no further change occurred at higher voltages. The phenomena are related to charge carrier (electrons) generation via cascade multiphoton ionization and exhibit excitation threshold dependence and non-linear behavior. Simultaneous measurements strongly highlight the connection between both processes. The occurrence of hysteresis suggests potential applications in artificial lighting and/or optical memory devices.

The online version contains supplementary material available at 10.1038/s41598-025-14109-6.