The effects of carrier transport phenomena on the spectral and power characteristics of blue superluminescent light emitting diodes N. Moslehi Milani a,b , A. Asgari b,c,n a Photonics–Electronics Group, Aras International Campus, University of Tabriz, Tabriz 51665-163, Iran b Photonics–Electronics Group, Research Institute for Applied Physics and Astronomy, University of Tabriz, Tabriz 51666-14766, Iran c School of Electrical, Electronic and Computer Engineering, The University of Western Australia, Crawley, WA 6009, Australia HIGHLIGHTS  In this article In 0.2 Ga 0.8 N/GaN-MQW superluminescent light emitting diodes has been investigated.  The effects of carrier escape, capture, and diffusion rates, and also carrier leakage are calculated.  The simulation is implemented at 300 K and at a constant current density of 15 kA/cm 2 .  The increasing of the drift leakage coefficient decreases the output power, significantly.  The escape times do not affect the SLD characteristics. GRAPHICAL ABSTRACT The effects of carrier escape, capture, and diffusion rates, and also carrier leakage term on the spectral and power characteristics of In 0.2 Ga 0.8 N/GaN multiple quantum well (MQW) superluminescent light emitting diodes (SLDs or SLEDs) has been investigated. Output spectral radiation power of studied SLD versus photon energy and (b7) output power as a function of current density for different drift leakage coefficients. article info Article history: Received 18 November 2014 Received in revised form 17 January 2015 Accepted 22 January 2015 Available online 23 January 2015 Keywords: InGaN/GaN Quantum well superluminescent diodes Carrier transport phenomena abstract In this article, the effects of carrier escape, capture, and diffusion rates, and also carrier leakage term on the spectral and power characteristics of In 0.2 Ga 0.8 N/GaN multiple quantum well (MQW) super- luminescent light emitting diodes (SLDs or SLEDs) has been investigated. The investigation is done by means of numerical analysis of the rate equations at steady state. In the model, a wide range of escape, capture, and diffusion times and also drift leakage coefficient correspond to the reported values have been examined in modeling procedure. The simulation is implemented at 300 K and at a constant cur- rent density of 15 kA/cm 2 . Our modeling results show that the escape times do not affect the SLD characteristics, but the variation of capture and diffusion times have moderate effects on output char- acteristics, while the increasing of the drift leakage coefficient decreases the output power significantly. & 2015 Elsevier B.V. All rights reserved. 1. Introduction Broadband light sources based on superluminescent light emitting diodes (SLDs or SLEDs) are optoelectronic devices with the char- acteristics of both a laser diode (LD) and light emitting diode (LED) [1]. They present highly directional LD beam and incoherent light emis- sion of an LED [2]. The beam directionality is caused high efficiency coupling with optical fiber systems. They are used for various appli- cations including optical coherence tomography (OCT) [3], wave- length-division-multiplexing (WDM) testing systems [4], speckle-free illumination [5]. Recent investigations have focused on producing blue SLEDs using GaN-based materials [6]. The first blue SLD have been reported in 2009 by Feltin et al. [7]. Short wavelength optoelectronic devices (UV to visible) can be used in spectroscopy, display lighting, projection systems [8] and medical applications [7]. Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/physe Physica E http://dx.doi.org/10.1016/j.physe.2015.01.035 1386-9477/& 2015 Elsevier B.V. All rights reserved. n Corresponding author at: Photonics–Electronics Group, Research Institute for Applied Physics and Astronomy, University of Tabriz, Tabriz 51666-14766, Iran. Fax: þ98 41 33347050. E-mail address: asgari@tabrizu.ac.ir (A. Asgari). Physica E 69 (2015) 165–170