Dynamic random access memory devices based on bismuth sulfide nanoplates prepared from a single source precursor

Semiconducting bismuth sulfide (Bi2S3) nanoplates with unique highly oriented {001} surfaces were prepared on a large scale using a novel organic precursor Bi(DTCA)3 (DTCA = carbazole-9-carbodithioic acid). The as-prepared Bi2S3 nanoplates were dispersed in dimethyl sulfoxide (DMSO) and spin-coated onto an indium tin oxide (ITO) coated glass substrate. With a simple ITO/Bi2S3/Al stacked structure, the fabricated sandwich-like memory device demonstrates dynamic random access memory (DRAM) characteristics with a maximum ON/OFF current ratio up to 10(6) and a long retention time. It is suggested that the volatile nature of the memory device comes from the Schottky contact between the Bi2S3 nanoplates and the Al electrodes.