DIAMOND BASED LIGHT-EMITTING STRUCTURES

Electrical and optical properties of diamond based light emitting diodes, with MIS (metal/insulator/semiconductor) and SIS (semiconductor/insulator/semiconductor) structures, were investigated. The devices were made by boron ion implantation and photolithography on polished surfaces of natural and synthetic diamonds and diamond films. Light emission is observed when electrical power is applied. Typical working parameters of natural diamond based devices are 150 V and 50 muA for 10 mum electrode spacing, or 20 V and 20 muA for 2 mum spacing. Light emission was observed in the temperature range 20-300-degrees-C. Depending on the luminescence properties of the initial diamond substrates, the devices show either the blue emission of the A-band, the green emission of the H3 centre, or the orange emission of the centre with 575 nm zero-phonon line. To explain the working mechanism of the devices, impact excitation of luminescence centres by hot carriers is proposed.