Solution-grown ternary quasi-cube AgSbTe2 and its optoelectronic performance for broadband photodetection

Abstract

Group I–V–VI₂ nanocrystals have been considered as potential candidates in the field of optoelectronics due to their highly tunable semiconductor characteristics. AgSbTe₂, one of the emerging group I–V–VI₂ nanocrystals with optical phase-change properties, a high light absorption coefficient and wide spectral response, is attractive for eco-friendly photodetector devices. However, a colloidal synthetic route for obtaining highly crystalline AgSbTe₂ nanocrystals with low toxicity precursors, which is vital to high-performance solution-processed photodetector devices, is still rare. Herein, we investigate the colloidal synthesis of quasi-cube AgSbTe₂ nanocrystals from the reaction of commercially available AgNO₃ with Sb(Ph)₃ in oleylamine at 190 °C, followed by the injection of a tellurium source, which was prepared by directly dissolving TeO₂ in 1-dodecanethiol. Simple AgSbTe₂/ITO heterostructure photodetectors were fabricated by a low-temperature colloidal synthetic route in combination with the spin-coating technique, which exhibit good photoresponse in a wide range from 405 to 980 nm with fast response times (0.49 and 0.58 s) and excellent stability. This work suggests that ternary silver-based I–V–VI₂ compound nanostructures have great potential for high-performance optoelectronic applications.