Current transport in ZnO/Si heterostructure grown by laser molecular beam epitaxy

Abstract

The n-ZnO/p-Si heterojunction was fabricated by depositing high quality single crystalline aluminium-doped n-type ZnO film on p-type Si using the laser molecular beam epitaxy technique. The heterojunction exhibited a good rectifying behavior. The electrical properties of the heterojunction were investigated by means of temperature dependence current density—voltage measurements. The mechanism of the current transport was proposed based on the band structure of the heterojunction. When the applied bias V is lower than 0.15 V, the current follows the Ohmic behavior. When 0.15 V < V < 0.6 V, the transport property is dominated by diffusion or recombination in the junction space charge region, while at higher voltages (V > 0.6 V), the space charge limited effect becomes the main transport mechanism. The current—voltage characteristic under illumination was also investigated. The photovoltage and the short circuit current density of the heterojunction aproached 270 mV and 2.10 mA/cm2, respectively.

Improvement in electroluminescence performance of n-ZnO/Ga 2 O 3 /p-GaN heterojunction light-emitting diodes

“…Due to the large direct band gap of 3.37 eV at room temperature (RT) and the high exciton binding energy of 60 mV, Zinc oxide (ZnO) has attracted considerable attention as a promising material for ultraviolet optoelectronic devices. [1,2] However, with great potential in electronic and photonic applications, there are few device applications of ZnO because it is a big problem to obtain high quality and stable p-type doping in ZnO. Thus, a heterojunction with an n-ZnO/p-GaN structure has been regarded as an alternative approach by virtue of their similarity in crystalline structure and closely matched lattice constant.…”