Blue-green light emission from Si and SiC quantum dots co-doped Si-Rich SiC p-i-n junction diode
Journal
IEEE Journal on Selected Topics in Quantum Electronics
Journal Volume
20
Journal Issue
4
Date Issued
2014
Author(s)
Abstract
Si quantum dots and SiC quantum dots (SiC-QDs) co-doped Si-rich silicon carbide (Si xC1-x) based p-i-n junction light-emitting diodes (LEDs) with blue light emission is demonstrated. By growing the Si xC1-x with plasma-enhanced chemical vapor deposition at relatively low temperature, the turn-on voltage of Si-rich SixC 1-x LEDs can be reduced to 6.1 V when thinning i-SixC 1-x layer to 25 nm because of higher tunneling probability and lower series resistance. The electroluminescent (EL) power increases to 136 nW, however, which inversely attenuates due to the reduced SiC-QDs if the i-Si xC1-x thickness further shrinks to 25 nm. The principle EL peak at 500 nm with narrower shape and blue-green emission pattern is attributed to the self-trapped excitons at surface states among SiC-QDs. The external quantum efficiency (EQE) of the Si-rich SixC1-x LEDs with i-SixC1-x thickness of 50 nm is up to 1.58 × 10-1% with enhanced carrier tunneling probability. The carrier injection efficiency is enhanced to 46% by increasing the doping concentration to 1016cm-3 , leading to almost one order of magnitude improvement on the EQE of Si-rich SixC1-x LEDs. © 1995-2012 IEEE.
Type
journal article