Giant enhancement of light emission from nanoscale Bi2Se3

Bi2Se3 is a well-known room temperature topological insulator with a gapless surface state and ∼300 meV bulk band-gap, and as such has never been proposed to possess light-emitting properties. Here, we report prominent light emission in the visible region via photoluminescence (PL) measurements of chemical vapor deposition grown Bi2Se3 nanoplates with an average thickness and effective diameter of tens of nanometers. When excited using 488 nm (2.54 eV) laser light, these nanoscale Bi2Se3 platelets show a strong photoluminescence response in the Eph ∼ 2.1–2.3 eV region, with significant enhancement of light emission compared to bulk level emission. After annealing samples at 200 °C for 4 h, PL intensity increased by a factor of 2.4 to 3 for nanoscale Bi2Se3.