Giant enhancement of optoelectronic properties in compressed boron-rich semiconductors

Optoelectronic devices often experience performance degradation under extreme conditions, such as elevated dark current and reduced sensitivity. Here we demonstrate that pressure uniquely enhances the optoelectronic performance of boron-rich semiconductor AlCu_1-δB₂₅ via an unconventional anti-Wilson effect. Under compression, the photocurrent of AlCu_1-δB₂₅ increases by more than 20-fold, to ∼7.22 μA at 26.5 GPa, while the dark current reduces dramatically by nearly four orders of magnitude (to ∼0.2 nA), yielding an unprecedented improvement in the on/off ratio exceeding 10⁵-fold. Simultaneously, pressure significantly accelerates the optoelectronic response, reducing the response time by three orders of magnitude. Optical absorption measurements reveal an anomalous pressure-driven anti-Wilson effect in AlCu_1-δB₂₅. First-principles calculations indicate that this anomaly arises from an upward shift of Al-3s states through interactions with B-2s electrons. Our findings underscore the significance of the anti-Wilson effect in optimizing optoelectronic properties and establish boron-rich semiconductors as promising candidates for harsh-environment devices.