Electrically pumped lasing from p-ZnO/n-GaN heterojunction diodes

A phosphorus-doped p-ZnO layer was prepared on an n-GaN/Al2O3 substrate by metal-organic chemical vapor deposition, and a heterojunction device was fabricated. The p-type doping of the device was confirmed by Hall, electrochemical capacitance-voltage and low-temperature photoluminescence measurements. Under forward bias, a random ultraviolet (UV) lasing phenomenon was detected from the p-ZnO:P/n-taN heterojunction light-emitting diode. The UV emission peak was centered at approximately 379 nm and was achieved from the ZnO side of the diode. The proposed diode provides a potentially valuable way to realize future high-efficiency ZnO lasers. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4740081]