PLD-derived Ge 2 Sb 2 Te 5 phase-change films with extreme bending stability for flexible device applications

Ge 2 Sb 2 Te 5 phase-change films on flexible mica substrates are prepared by pulsed laser deposition (PLD). X-ray diffraction measurements determine the crystallographic phase of the as-deposited films and confirm that the ⟨ 111 ⟩ is the preferential orientation of growth. Temperature-dependent Raman and electrical measurements show that phase transitions from the amorphous to rock salt and hexagonal structures occur at 420 K and 550 K, respectively. Here, we have assembled a flexible electronic device with aluminum alloy sheet and silver glue for fixing after bending. Two significant resistance drops, encompassing four orders and two orders of magnitude, can be observed at the transition temperatures ranging from 420 K to 550 K. The switching ratio of the flexible devices is maintained at six orders of magnitude under different bending states. The present results demonstrate an excellent potential for applications of these PLD-deposited Ge 2 Sb 2 Te 5 films on mica substrates in flexible data storage and neuro-inspired computing.