Room temperature electroluminescence from a nanocrystalline diamond/Si heterojunction

We report on the fabrication and characterization of the room temperature electroluminescence of heterojunction between nanocrystalline diamond film (NDF) and heavily doped n-type single crystalline silicon (n+-Si) substrate. The current–voltage characteristics (I–V) of the NDF/n+-Si heterojunction show clear rectification properties. Importantly, with sufficiently high forward bias applied on the NDF/n+-Si heterojunction, fairly strong visible electroluminescence (EL) was obtained at room temperature. The EL occurred as the consequence of the electrons tunneling from the n+-Si into the NDF. An energy-band model has been proposed to understand the mechanism of the I–V characteristics and the EL for the NDF/n+-Si heterojunction.