Ultrawide band quantum dot light emitting device by postfabrication laser annealing

An ultrawide band quantum dot (QD) light emitting device (LED) with bandwidth of 360 nm covering 1284-1644 nm spectral range has been demonstrated by postfabrication laser-irradiation technique. The integrated light output of the QD LED was found to increase by four times after laser annealing, attributed to the improved homogeneity of the QDs and enhanced lateral electrical and optical confinements at the active region after intermixing. Large wavelength blueshift of 315 nm has been obtained at the laser annealed region and an overall increase in bandwidth of 22% has been obtained in the QD LED after postfabrication laser annealing.