Pyro-phototronic Effect Enhanced Self-Powered Photoresponse in Lead-Free Hybrid Perovskite

Pyro-phototronic effect (PPE) can significantly boost
the performance
of hybrid perovskite (HPs) photodetectors due to the effective modulation
of photogenerated charge carrier separations, transportation, and
extraction. However, there are few reports on the application of PPE
in lead-free HPs. Herein, a polar lead-free HP (1,3-BMACH)BiBr5 [1,3-BMACH = 1,3-bis(aminomethyl)cyclohexane]
is synthesized and realized broadband self-powered photoresponse
from X-rays to near-infrared (NIR) through the PPE. Particularly,
this light-induced PPE in lead-free HPs breaks the limitation of the
optical band gap, making them suitable for broadband self-powered
photodetection. Under 405 nm illumination, compared with a purely
photovoltaic system, Iphoto+pyro is boosted
by 3100%, and R and D* are both
enhanced by 260% after coupled PPE. It is particularly interesting
that an obvious X-ray-induced PPE phenomenon is also observed, which
endows (1,3-BMACH)BiBr5 with a high sensitivity of 154
μC Gy–1 cm–2 and a low detection
limit of 307 nGy s–1 under the self-powered mode.
The implementation of light-induced PPE from X-rays to NIR in lead-free
HPs provides a new approach for constructing environmentally friendly,
broadband, and self-powered optoelectronic devices in the future.