Discovery of Unamorphizable Semiconductor

Radiation tolerance is determined as the ability of crystalline materials to withstand the accumulation of the radiation induced disorder. Nevertheless, for sufficiently high fluences, in all by far known semiconductors it ends up with either very high disorder levels or amorphization. Here we show that gamma/beta (γ/β) double polymorph Ga₂O₃ structures exhibit remarkably high radiation tolerance [1]. Specifically, for room temperature experiments, they tolerate a disorder equivalent to hundreds of displacements per atom, without severe degradations of crystallinity; in comparison with, e.g., Si amorphizable already with the lattice atoms displaced just once. We explain this behavior by an interesting combination of the Ga- and O- sublattice properties in γ-Ga₂O₃. In particular, O-sublattice exhibits a strong recrystallization trend to recover the face-centered-cubic stacking despite the stronger displacement of O atoms compared to Ga during the active periods of cascades. Notably, we also explained the origin of the β-to-γ Ga₂O₃ transformation, as a function of the increased disorder in β-Ga₂O₃ and studied the phenomena as a function of the chemical nature of the implanted atoms. As a result, we conclude that γ/β double polymorph Ga₂O₃ structures, in terms of their radiation tolerance properties, benchmark a class of universal radiation tolerant semiconductors.<br/>[1] Azarov, A., Fernández, J.G., Zhao, J. <i>et al.</i> Universal radiation tolerant semiconductor. <i>Nat Commun</i> <b>14</b>, 4855 (2023).