Unconventionally anisotropic growth of PbSe nanorods: Controllable fabrication under solution-solid-solid regime over Ag₂Se catalysis for broadband photodetection

Broadband optoelectronic devices intrigue enormous interests on account of their promising potential in optical communications, sensors and environmental monitoring. PbSe nanocrystals are promising candidates for the construction of next-generation photodetectors due to their fascinating intrinsic properties and solution-processed compatibility with varied substrates. Here, we report the fabrication of a broadband photodetector on the basis of high-quality solution-processed PbSe nanorods in rock-salt phase grown along unconventionally anisotropic growth direction of < 112 > zone axis. The rock-salt PbSe nanorods are synthesized in solution phase over the catalysis of Ag₂Se with relatively high-temperature body-centered cubic phase via a solution-solid-solid growth regime using oleylamine and oleic acid as solvents and stabilizer surfactants, from which the PbSe nanorods with the unconventionally anisotropic growth direction are controllably grown in size and shape in the synthetic procedure typically with about 17 nm in diameter and 58 nm in length on average. Meanwhile, the PbSe nanorods-based photodetector exhibits a broadband response from 405 to 1, 064 nm with a high responsivity of 0.78 A·W⁻¹ and a fast response time of 17.5 µs. The response time is much faster in comparison with most of the PbSe-based photodetectors with response time in millisecond level.