Highly Reactive Crystalline (001) Facet of BiI3 Hexagonal Nanoplates for Visible Light Photodetectors

A simple and facile solution phase synthesis of large-scale,micro-to-nanometersized bismuth triiodide (BiI3) single crystalline hexagonalplates is reported. It is demonstrated that under optimized conditionsthe reactions result in dominant exposed (001) facets. Because ofthe large size, high surface-to-volume ratio, and thickness, BiI3 nanoplatelets are attractive as visible light photodetectors.At 1 V bias, the photoresponsivity is 0.87 A W-1; the specific detectivity is 4.8 x 10(12) jones witha response rise time of 1 s and a fall time of 0.97 s. The Kelvinprobe force microscope images revealed that the surface potentialdifference across the junction was 42.5 mV, which is attributed tothe work function difference between the sample and substrate. Theresults of this study indicate that single hexagonal platelets ofBiI(3) are very promising for visible light photodetectorapplications.

Automated summary

A simple solution phase synthesis of large-scale BiI3 single crystalline hexagonal plates with dominant (001) facets is reported. These BiI3 nanoplatelets have attractive properties for visible light photodetectors due to their large size, high surface-to-volume ratio, and thickness. The photodetector performance includes a photoresponsivity of 0.87 A W-1 at 1 V bias and specific detectivity of 4.8 x 10(12) jones, with fast response rise and fall times of 1 s and 0.97 s, respectively. The study also reveals the surface potential difference between the sample and substrate, making these hexagonal platelets promising for visible light photodetection applications.