# Theoretical Study of Ultra-Fast Laser Lift-Off of Carbon Nanotube-Integrated Polyimide Films

## TL;DR

This study uses simulations to show that picosecond lasers with specific pulse intervals and CNT integration can improve laser lift-off of polyimide films with lower energy.

## Contribution

A new PI/CNT/glass model is proposed for ultra-fast laser lift-off with reduced energy requirements.

## Key findings

- Picosecond lasers cause higher lattice temperature increases at the PI interface under specific pulse intervals.
- CNT integration at the PI/glass interface significantly increases lattice temperature under picosecond laser irradiation.
- The integration of CNTs reduces the laser energy threshold required for the LLO process.

## Abstract

In this paper, ultra-fast laser lift-off (LLO) of carbon nanotube (CNT)-integrated polyimide film (PI) was investigated by different laser burst mode and pulse intervals using the two-temperature model. By comparing the temperature field distributions of nanosecond, picosecond, and femtosecond lasers at different pulse intervals, it can be found that picosecond lasers cause a higher lattice temperature increase at the PI interface with specific pulse interval conditions. With the increase in the pulse interval, the lattice temperature of the three kinds of lasers decreased, indicating that the heat accumulation effect was weakened. In addition, under picosecond laser irradiation, the lattice temperature at the PI/glass interface of integrated CNTs could be significantly increased, which was significantly different from the system without integrated CNTs. The simulation results show that the picosecond laser is more suitable for LLO with an appropriate pulse interval, and the integration of CNTs at the PI/glass interface can effectively reduce the laser energy threshold required for the LLO process. Our work presents a new PI/CNT/glass model for ultra-fast laser low-threshold LLO and promotes the laser debonding technology in the fields of OLED and other optoelectronic chips.