Ultraviolet laser quantum well intermixing based prototyping of bandgap tuned heterostructures for the fabrication of superluminescent diodes

Bandgap Engineering of Quantum Semiconductor Microstructures

“…22 Emission spectra from SLD devices fabricated in sample B (Intermixed SLD) and in asgrown non-irradiated non-annealed material (Reference SLD). The output power emitted in both cases is 1.1 mW (Beal et al 2016) pushing back some of those limits. In this chapter, a general idea has been introduced of a laser as the attractive tool for direct fabrication of unique microstructures (e.g., graded bandgap semiconductor materials) or processing of state-of-the-art thin films for delivering devices unattainable, or not easily attainable with conventional methods (e.g., arbitrary 2D patterns of different bandgap materials, high-power superluminescent diodes).…”

“…The most common approach addressing this problem takes advantage of heterostructures with broad gain spectra achieved with multiple width QW architectures, large-size distribution QD microstructures, or a combination of both QW and QD microstructures. Postgrowth intermixing has been investigated to increase spectral emission range of QW wafers using IR Laser-RTA (Beal et al 2013), although UV Laser-QWI seems to offer more control over the process and, consequently, devices of superior quality (Beal et al 2016). Figure 21 shows cross-section profiles of QW PL peak emission (λ PL ) measured across InP capped InGaAs/InGaAsP QW samples irradiated with the KrF laser selectively in one section with 60 pulses (sample A), and in two sections with 15 and 60 pulses (Beal et al 2016).…”

“…Postgrowth intermixing has been investigated to increase spectral emission range of QW wafers using IR Laser-RTA (Beal et al 2013), although UV Laser-QWI seems to offer more control over the process and, consequently, devices of superior quality (Beal et al 2016). Figure 21 shows cross-section profiles of QW PL peak emission (λ PL ) measured across InP capped InGaAs/InGaAsP QW samples irradiated with the KrF laser selectively in one section with 60 pulses (sample A), and in two sections with 15 and 60 pulses (Beal et al 2016). The fabrication of 2-and 3-bandgap materials is clearly illustrated: sample A emits in the non-irradiated region at 1512 nm, while its emission has been blueshifted by 74 nm to 1438 nm in the laser processed region.…”

“…It can be seen that the architecture of an SLD device based on a 3-bandgap material allowed increasing the width of an emitted spectrum by 2.5 times (FWHM%100 nm) in Fig. 21 PL peak wavelength profiles generated with the UV-Laser-QWI process across two InGaAs/InGaAsP QW samples (Beal et al 2016) comparison to the spectrum emitted by a device fabricated from a non-intermixed material (FWHM%40 nm).…”