Experimental study demonstrates enhanced stability and high detectivity in lead-free double perovskite photodetectors, suggesting viable nontoxic optical sensing.
Key Points
Synthesize a lead-free Cs2Ag0.75Bi0.75Ba0.5I6 double perovskite to overcome phase instability and evaluate its performance in high-efficiency photodetectors.
Synthesized Cs2Ag0.75Bi0.75Ba0.5I6 using a solvent-free mechanochemical ball-milling route.
Verified B-site substitution of Ba2+ at 0.5 site occupancy and analyzed crystal phase using ICP-MS and XRD.
Fabricated photodetector devices to characterize dark current, specific detectivity, optical bandwidth, and 30-day stability.
Ba2+ substitution enhanced crystallinity and phase stability while reducing dark current by 250-fold.
The optimized photodetector achieved a peak specific detectivity of 2.17 × 10^10 Jones and retained 95% of performance after 30 days of storage.
The device demonstrated sub-bandgap photoresponse at 785 and 1064 nm, a 3-dB bandwidth of 1.493 MHz, and distortion-free recovery of 500 kHz signals.