Photon bunching reveals single-electron cathodoluminescence excitation efficiency in InGaN quantum wells

Cathodoluminescence hyperspectral analysis of whispering gallery modes in active semiconductor wedge resonators

“…Contrary to the work of Sapienza et al [2] where the LDOS is measured within the band gap of a dielectric- material photonic-crystal device, with the electron beam acting directly as a broadband dipole source, known as coherent excitation [15,16], our measurements should more likely originate from incoherent excitation consisting in the creation and relaxation of many electron-hole pairs down to the active material of the photonic structure, namely quantum wells (QWs)and subsequent radiative recombination [17]. In some cases coherent emission processes can also be observed above the semiconductor band gap emission [18] and photon correlation experiments then become necessary to identify the coherent and incoherent contributions to the signal [19].…”

Free chargesversusexcitons: photoluminescence investigation of InGaN/GaN multiple quantum well nanorods and their planar counterparts

“…InGaN/GaN MQW planar layers were grown on a c-plane sapphire substrate by metalorganic vapor phase epitaxy (MOVPE). 26 Densely packed nanorods were then fabricated using a top-down etching method, as previously reported. 8 Detailed layer stacks are shown in Fig.…”

Nanoscale Relative Emission Efficiency Mapping Using Cathodoluminescence g(2) Imaging

“…As the beam current is known for a given data acquisition, τ e and γ can be determined independently from the g (2) data. 20 In this way, the excitation efficiency γ can be extracted for any position on the sample without a priori knowledge on the sample geometry, a major advantage in complex 3D semiconductor geometries as we will show.…”

“…(See Figure 2 a.) The CL data have been calibrated using the method described in refs ( 20 ) and ( 24 ) using the known electron current (52 pA) as the input, yielding the average number of photons emitted per incident electron per unit bandwidth.…”

“…In this case, the pixels are displayed as white in the maps. Next, using the statistical model described in ref ( 20 ), we derive the probability of excitation γ, defined as the fraction of electrons that excite the optically active regions (QWs), for each pixel. The input parameters for this analysis are the beam current (52 pA), the lifetime τ e , and the amplitude g (2) (0)-1.…”