# Giant enhancement of optoelectronic properties in compressed boron-rich semiconductors

## TL;DR

Applying pressure significantly improves the optoelectronic performance of a boron-rich semiconductor, making it a promising material for high-performance devices.

## Contribution

The study reveals a pressure-induced anti-Wilson effect that enhances optoelectronic properties in AlCu1-δB25.

## Key findings

- Compression increases photocurrent by over 20-fold and reduces dark current by nearly four orders of magnitude.
- Pressure reduces optoelectronic response time by three orders of magnitude.
- The anti-Wilson effect is linked to an upward shift of Al-3s states interacting with B-2s electrons.

## Abstract

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 AlCu1-δB25 via an unconventional anti-Wilson effect. Under compression, the photocurrent of AlCu1-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 AlCu1-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.

Pressure-induced bandgap widening in boron-rich semiconductors AlCu1-δB25 synergistically optimizes the on/off ratio and response time, offering a novel strategy for enhancing optoelectronic performance.