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 (SiN_x ) matrix growth, have been studied. Si-QDs are formed in-situ during the SiN_x 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 SiN _x grown with ammonia (NH₃) are located at the interface between the SiN_x 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.