Retention of high-pressure solution-processable metastable phase to ambience via differential sublattice rigidity for broadband photodetectors.

Abstract

Materials science exploits only properties that are available at ambience. Therefore, although high-pressure changes the physical state of all condensed matter, most of the extraordinary properties discovered vanish after decompression and cannot be utilized. Here, we demonstrate sublattice decoupling in a mixed-anion chalcohalide Rb₆Re₆S₈I₈ upon compression, in which the [Rb₆I₂]⁴⁺ framework is soft and plastic, while the [Re₆S₈I₆]^4- clusters are hard and elastic. This discrepancy in the rigidity allows the applied pressure to selectively amorphize the framework while maintaining the ordered state in the cluster, leading to intriguing photocurrent generation and enhancement upon compression. These high-pressure properties are retained at ambience, permitting scalable synthesis of the decompressed samples using a large-volume press, followed by further fabrication into self-powered broadband photodetectors with a response time of ~ 10² μs and a specific detectivity of ~ 10¹¹ Jones. This study subverts the stereotype that pressure engineering is hardly to be employed for device applications.