Photoluminescence from localized states in disordered indium nitride

Abstract

Photoluminescence spectra from disordered InN were studied in very high magnetic fields. The samples had Gaussian spectra with low temperature emission peaks at 0.82 and 0.98eV respectively. The average spatial extent of the excitonic wave functions, inferred from the diamagnetic shift, is only 2-3nm. This shows that the recombination is from an ensemble of highly localized states within a landscape of a smooth (classical) disorder potential of strength of the order of 10meV. The anomalies in the temperature dependence of the photoluminescence peak and linewidth give further support to the picture of trapped photoexcited carriers.

Determining the Optimized Interlayer Separation Distance in Vertical Stacked 2D WS2:hBN:MoS2 Heterostructures for Exciton Energy Transfer

“…The exciton and trion peak positions at different laser powers are studied in Figure S7 (Supporting Information). Additionally, the increased LS emissions reveal more structural disorders caused by the strain (Figure i,j,l,m vs Figure a,b,d,e, respectively) . The influences of strain can be minimized with high laser input, where the activity of dipoles across the WS 2 and MoS 2 layers is increased and closer to saturation.…”

“…In addition, the B peak of monolayer MoS 2 is located at a higher energy, which originates from another direct transition between the conduction and valence bands. The LS peak is normally related to structural disorders and/or impurities . The ratio of exciton/trion decreases for both the “pristine” TMDs and the heterostructure.…”

“…The LS peak is normally related to structural disorders and/or impurities. [33,39,40] The ratio of exciton/ trion decreases for both the "pristine" TMDs and the heterostructure. Figure 2a,d shows that the total PL of the WS 2 :1 × hBN:MoS 2 stack is primarily made up of the emission from WS 2 , which is substantially stronger than that from MoS 2 .…”

Light emission despite doubly-forbidden radiative transitions in AlP/GaP quantum wells: Role of localized states

“…The extent of the bound hole wave function, d, can be estimated from the uncertainty argument, d % h= ffiffiffiffiffiffiffiffiffiffiffiffiffi ffi 2m h E B p . 22 With the heavy hole mass in GaP m h ¼ 0:67m 0 , where m 0 is the free electron mass, and localization energy E B % 35 meV, we get d % 1:2 nm, that is about two lattice constant. Such strongly localized hole states would have a considerable spread in their momentum states which would support phonon-free recombination in this indirect gap system.…”

Strong composition-dependent disorder in InAs1−xNx alloys

“…We underline here that the band gap energies of InN and InAs are still controversial. We address the reader to some recent papers on the matter [27][28][29][30][31][32][33] regarding these compounds in the extreme limits of the alloy. Fig.…”