Luminescence ofCu2O-Excitonic Molecules, or Not?

Breaking of Raman selection rules in Cu2O by intrinsic point defects

“…The spectra shown are taken of various Cu 2 O samples, i. e. a bulk crystalline sample as well as thin film samples grown by molecular beam epitaxy (MBE), chemical vapour deposition (CVD), rfsputtering, and oxidized copper recorded at room temperature in backscattering geometry using a 532 or 633 nm laser for excitation. Very similar spectra of bulk Cu 2 O crystals are reported in the literature [6][7][8][9][10][11][12][13]. The main finding basically is that one observes all lattice modes as one-phonon Raman signals in the spectra: a T 2u mode at about 90 cm -1 , a E u mode at 110 cm -1 , LO and TO modes of T 1u symmetry between 140-160 cm -1 , a A 2u mode at about 350 cm -1 , and LO and TO modes of T 1u symmetry between 630-660 cm -1 , and in the vicinity of 515 cm -1 the only Raman active LO and TO T 2g modes.…”

Use of silane agents and poly(propylene‐g‐maleic anhydride) copolymer as adhesion promoters in glass fiber/polypropylene composites

“…30 exhibits pronounced differences, as it reveals a multitude of Raman signals. However, it is similar to the experimental spectra of bulk Cu 2 O crystals reported in the literature 131–135. It is worth noting that the reported Raman spectra vary significantly in the mode intensities and the number of observed modes.…”

Excitonic Effects in Emerging Photovoltaic Materials: A Case Study in Cu2O

“…The unusual peak shape is due to the convolution of the orthoexciton peak and the phononassisted exciton peak, which broadens and grows at higher temperatures where the absorption probability of phonons by excitons is large. 5,[21][22] The peak was evident even at the lowest of excitation powers (0.85 µW). Thus, excitons are generated under visible excitation even in polycrystalline Cu 2 O substrates used in photovoltaic fabrication.…”