Electroluminescent silicon device

PCT No. PCT/GB92/00547 Sec. 371 Date Oct. 8, 1993 Sec. 102(e) Date Oct. 8, 1993 PCT Filed Mar. 25, 1992 PCT Pub. No. WO92/19084 PCT Pub. Date Oct. 29, 1992An electroluminescent silicon device (10) includes a silicon structure (12) which comprises a bulk silicon layer (14) and a porous silicon layer (16). The porous layer (16) has merged pores (20) which define silicon quantum wires (18). The quantum wires (18) have a surface passivation layer (22). The porous layer (16) exhibits photoluminescence under ultra-violet irradiation. The porous layer (16) is pervaded by a conductive material such as an electrolyte (24) or a metal (48). The conductive material (24) ensures that an electrically continuous current path extends through the porous layer (16); it does not degrade the quantum wire surface passivation (22) sufficiently to render the quantum wires (18) non-luminescent, and it injects minority carriers into the quantum wires. An electrode (26) contacts the conductive material (24) and the bulk silicon layer has an Ohmic contact (28). When biased the electrode (26) is the anode and the silicon structure (12) is the cathode. Electroluminescence is then observed in the visible region of the spectrum.