Effects of the Hole Tunneling Barrier Width on the Electrical Characteristic in Silicon Quantum Dots Light-Emitting Diodes

Electrical properties of the Silicon quantum dots (Si-QD) light-emitting diodes (LEDs), in its dependence on the nitrogen source used in the silicon nitride (SiNx) matrix growth, have been studied. Si-QDs are formed in-situ during the SiNx film growth, and no post-annealing process for crystallization was applied. To confirm the electrical properties of the Si-QD devices, we manufacture the Si-QD LED. Both p-type and p(+)-type Si substrate were tested in role of hole tunneling in the LED performance. The high-resolution transmission electron microscopy (HRTEM) analyses and the current-voltage (I-V) measurement show that the Si-QDs embedded in the SiNx grown with ammonia (NH3) are located at the interface between the SiNx film and the Si substrate. This is related to the observed increase in the forward current by considering a decrease in the hole tunneling barrier width between the Si substrate and the Si-QDs. (C) 2011 The Japan Society of Applied Physics